AQA GCSE · Thinka-original Practice Paper

2024 AQA GCSE Mathematics 8300 Practice Paper with Answers

Thinka Nov 2024 AQA GCSE-Style Mock — Mathematics 8300

240 marks270 mins2024
An original Thinka practice paper modelled on the structure and difficulty of the Nov 2024 AQA GCSE Mathematics 8300 paper. Not affiliated with or reproduced from AQA.

Paper 1 (Non-Calculator)

Answer all questions in the spaces provided. You must not use a calculator.
40 Question · 77.80000000000004 marks
Question 1 · fill-in
1.5 marks
Work out the value of \( 1.5 \times (3.2 + 4.8) - 2.5^2 \).
Show answer & marking scheme

Worked solution

First, calculate the brackets: \( 3.2 + 4.8 = 8.0 \). Next, perform the multiplication: \( 1.5 \times 8 = 12 \). Then, calculate the square: \( 2.5^2 = 6.25 \). Finally, subtract: \( 12 - 6.25 = 5.75 \).

Marking scheme

M1 for a correct intermediate step, such as finding the bracket sum is 8, or calculating \( 1.5 \times 8 = 12 \), or evaluating \( 2.5^2 = 6.25 \). A0.5 for the correct final answer of 5.75 (or equivalent fraction, e.g. \( \frac{23}{4} \) or \( 5\frac{3}{4} \)).
Question 2 · fill-in
1.5 marks
A map has a scale of \( 1 : 25\,000 \). The distance between two towns on the map is \( 8.4\text{ cm} \). Work out the actual distance in kilometres.
Show answer & marking scheme

Worked solution

Actual distance in cm is \( 8.4 \times 25\,000 = 210\,000\text{ cm} \). To convert centimetres to metres, divide by 100: \( 210\,000 \div 100 = 2100\text{ m} \). To convert metres to kilometres, divide by 1000: \( 2100 \div 1000 = 2.1\text{ km} \).

Marking scheme

M1 for correctly scaling up the map distance, e.g. \( 8.4 \times 25\,000 \) or finding \( 210\,000\text{ cm} \), or showing a correct method for converting cm to km (dividing by 100,000). A0.5 for 2.1.
Question 3 · fill-in
1.5 marks
Simplify fully \( \frac{12x^2 y}{18x y^3} \).
Show answer & marking scheme

Worked solution

To simplify the expression, find the greatest common divisor for each part. For the coefficients, \( \gcd(12, 18) = 6 \), which simplifies \( \frac{12}{18} \) to \( \frac{2}{3} \). For the variable parts, simplify \( \frac{x^2}{x} = x \) and \( \frac{y}{y^3} = \frac{1}{y^2} \). Combining these gives \( \frac{2x}{3y^2} \).

Marking scheme

M1 for simplifying the coefficients to \( \frac{2}{3} \) or correctly simplifying at least one of the algebraic terms (e.g., getting \( x \) in the numerator or \( y^2 \) in the denominator). A0.5 for \( \frac{2x}{3y^2} \) or equivalent expression.
Question 4 · fill-in
1.5 marks
A biased spinner can land on Red, Blue or Yellow. The probability of landing on Red is 0.4. The probability of landing on Blue is twice the probability of landing on Yellow. Work out the probability of landing on Blue.
Show answer & marking scheme

Worked solution

The total sum of probabilities must equal 1. Let the probability of landing on Yellow be \( x \). This means the probability of landing on Blue is \( 2x \). Setting up the equation: \( 0.4 + 2x + x = 1 \) which simplifies to \( 0.4 + 3x = 1 \). Subtract 0.4 from both sides to get \( 3x = 0.6 \), giving \( x = 0.2 \). Therefore, the probability of Blue is \( 2 \times 0.2 = 0.4 \).

Marking scheme

M1 for setting up a correct equation or finding the sum of the remaining probabilities, e.g., \( 1 - 0.4 = 0.6 \) and writing \( 3x = 0.6 \). A0.5 for 0.4.
Question 5 · fill-in
1.5 marks
Solve the equation \( \frac{2x - 3}{5} = 4 \).
Show answer & marking scheme

Worked solution

Multiply both sides of the equation by 5: \( 2x - 3 = 20 \). Add 3 to both sides: \( 2x = 23 \). Divide by 2: \( x = 11.5 \) or \( \frac{23}{2} \).

Marking scheme

M1 for a correct first step to isolate the numerator, e.g., \( 2x - 3 = 20 \). A0.5 for 11.5 (accept \( 11\frac{1}{2} \) or \( \frac{23}{2} \)).
Question 6 · fill-in
1.5 marks
Out of 80 students, 28 walk to school. What percentage of the students walk to school?
Show answer & marking scheme

Worked solution

First, write the proportion of students who walk as a fraction: \( \frac{28}{80} \). Simplify this fraction by dividing both the numerator and the denominator by 4: \( \frac{7}{20} \). To turn this into a percentage, multiply by 100: \( \frac{7}{20} \times 100 = 7 \times 5 = 35\% \).

Marking scheme

M1 for writing the fraction \( \frac{28}{80} \) and attempting to simplify it or multiply by 100. A0.5 for 35 (accept 35%).
Question 7 · fill-in
1.5 marks
Work out the size of an interior angle of a regular octagon.
Show answer & marking scheme

Worked solution

Method 1: A regular octagon has 8 sides. The sum of the exterior angles is \( 360^\circ \), so each exterior angle is \( 360^\circ \div 8 = 45^\circ \). Since the interior and exterior angles sum to \( 180^\circ \), each interior angle is \( 180^\circ - 45^\circ = 135^\circ \). Method 2: Use the formula for the sum of interior angles: \( (8 - 2) \times 180^\circ = 6 \times 180^\circ = 1080^\circ \). Divide by the number of angles: \( 1080^\circ \div 8 = 135^\circ \).

Marking scheme

M1 for finding the exterior angle \( 360 \div 8 = 45 \), or showing a correct calculation for the sum of interior angles \( (8-2) \times 180 \). A0.5 for 135.
Question 8 · fill-in
1.5 marks
Find the \(n\)-th term of the sequence: 5, 11, 17, 23, 29, ...
Show answer & marking scheme

Worked solution

First, find the common difference between consecutive terms: \( 11 - 5 = 6 \). This means the formula contains \( 6n \). Compare the sequence \( 6n \) (which is 6, 12, 18, 24, ...) with the given sequence (5, 11, 17, 23, ...). We can see that each term in our sequence is 1 less than the corresponding term of \( 6n \). Therefore, the \(n\)-th term is \( 6n - 1 \).

Marking scheme

M1 for identifying a common difference of 6 or writing an expression of the form \( 6n + c \) where \( c \) is any integer constant. A0.5 for \( 6n - 1 \) (or equivalent).
Question 9 · short_answer
1.5 marks
Write \(0.1\dot{7}\) as a fraction in its simplest form.
Show answer & marking scheme

Worked solution

Let \(x = 0.1\dot{7} = 0.1777...\)
Multiply by 10:
\(10x = 1.777...\)
Multiply by 100:
\(100x = 17.777...\)
Subtracting the two equations:
\(100x - 10x = 17.777... - 1.777...\)
\(90x = 16\)
\(x = \frac{16}{90} = \frac{8}{45}\)

Marking scheme

M1 for setting up two appropriate equations, e.g., \(10x = 1.77...\) and \(100x = 17.77...\), and subtracting them to get \(90x = 16\) or equivalent.
A0.5 for \(\frac{8}{45}\) (must be fully simplified).
Question 10 · short_answer
1.5 marks
Bill and Ted share some money in the ratio \(5 : 3\). Bill receives \(\pounds 24\) more than Ted. Work out the total amount of money shared.
Show answer & marking scheme

Worked solution

The difference in parts between Bill and Ted is \(5 - 3 = 2\) parts.
Since Bill receives \(\pounds 24\) more than Ted, these 2 parts represent \(\pounds 24\).
Therefore, 1 part is \(\frac{\pounds 24}{2} = \pounds 12\).
The total number of parts is \(5 + 3 = 8\) parts.
The total amount of money shared is \(8 \times \pounds 12 = \pounds 96\).

Marking scheme

M1 for finding the value of one part: \(\frac{24}{5 - 3} = 12\) or setting up an equation such as \(5x - 3x = 24\).
A0.5 for \(96\) (or \(\pounds 96\)).
Question 11 · short_answer
1.5 marks
Solve the inequality \(5(x - 2) > 3x + 7\).
Show answer & marking scheme

Worked solution

First, expand the bracket on the left-hand side:
\(5x - 10 > 3x + 7\)
Next, subtract \(3x\) from both sides:
\(2x - 10 > 7\)
Then, add 10 to both sides:
\(2x > 17\)
Finally, divide by 2:
\(x > 8.5\) (or \(x > \frac{17}{2}\))

Marking scheme

M1 for correctly expanding the bracket and collecting like terms on both sides to get \(2x > 17\) (or equivalent).
A0.5 for \(x > 8.5\) or \(x > \frac{17}{2}\).
Question 12 · short_answer
1.5 marks
Simplify fully \(\frac{(3x^3 y^2)^3}{9x^4 y^5}\).
Show answer & marking scheme

Worked solution

First, simplify the numerator by applying the power of 3 to each term inside the brackets:
\((3x^3 y^2)^3 = 3^3 \times (x^3)^3 \times (y^2)^3 = 27x^9y^6\)
Now, divide this by the denominator:
\(\frac{27x^9y^6}{9x^4y^5} = \frac{27}{9} \times x^{9-4} \times y^{6-5} = 3x^5y\)

Marking scheme

M1 for expanding the numerator correctly to \(27x^9y^6\), or for correctly dividing indices with at most one arithmetic slip.
A0.5 for \(3x^5y\) (or \(3x^5y^1\)).
Question 13 · short_answer
1.5 marks
Given that \(A = 2^3 \times 3^2 \times 5\) and \(B = 2^2 \times 3 \times 7\), find the highest common factor (HCF) of \(A\) and \(B\).
Show answer & marking scheme

Worked solution

To find the highest common factor (HCF), we identify the common prime factors in both numbers and choose the lowest power for each.
The common prime factors are 2 and 3.
The lowest power of 2 is \(2^2\).
The lowest power of 3 is \(3^1\) (or 3).
Therefore, the \(\text{HCF} = 2^2 \times 3 = 4 \times 3 = 12\).

Marking scheme

M1 for identifying the correct common prime factors with their lowest powers, e.g., writing \(2^2 \times 3\) or listing factors of both numbers to find common ones.
A0.5 for \(12\).
Question 14 · short_answer
1.5 marks
A bag contains 4 red counters and 6 blue counters. A counter is drawn at random, its colour is noted, and it is replaced. A second counter is then drawn at random. Work out the probability that both counters are red.
Show answer & marking scheme

Worked solution

The total number of counters in the bag is \(4 + 6 = 10\).
The probability of drawing a red counter on the first draw is \(\frac{4}{10} = \frac{2}{5}\).
Since the counter is replaced, the probability of drawing a red counter on the second draw is also \(\frac{2}{5}\).
Since these are independent events, the probability of both being red is:
\(\frac{2}{5} \times \frac{2}{5} = \frac{4}{25}\) (or \(0.16\))

Marking scheme

M1 for finding the probability of drawing one red counter (\(\frac{4}{10}\) or \(0.4\)) and multiplying it by itself, i.e., \(\frac{4}{10} \times \frac{4}{10}\).
A0.5 for \(\frac{4}{25}\) or equivalent fraction (e.g., \(\frac{16}{100}\)) or decimal (\(0.16\)).
Question 15 · Structured Working
2.2 marks
Work out the value of \( 125^{-\frac{2}{3}} \). Give your answer as a fraction.
Show answer & marking scheme

Worked solution

First, we address the negative exponent by taking the reciprocal:
\( 125^{-\frac{2}{3}} = \frac{1}{125^{\frac{2}{3}}} \)

Next, evaluate the cube root (the denominator of the fractional exponent):
\( 125^{\frac{1}{3}} = \sqrt[3]{125} = 5 \)

Then, square the result:
\( 5^2 = 25 \)

Combining these steps gives:
\( 125^{-\frac{2}{3}} = \frac{1}{25} \)

Marking scheme

M1 for correctly identifying the cube root of 125 is 5, e.g., showing \( 125^{\frac{1}{3}} = 5 \) or \( (5^3)^{-\frac{2}{3}} \) or writing \( \frac{1}{125^{\frac{2}{3}}} \)
A1 for \( \frac{1}{25} \)
Question 16 · Structured Working
2.2 marks
Solve the inequality \( x^2 - 2x - 15 \le 0 \).
Show answer & marking scheme

Worked solution

First, solve the quadratic equation \( x^2 - 2x - 15 = 0 \) to find the critical values.
Factorising the quadratic expression:
\( (x - 5)(x + 3) = 0 \)
This gives the critical values:
\( x = 5 \) and \( x = -3 \)

Since we require \( x^2 - 2x - 15 \le 0 \), the solution lies on or between the two critical values on a graph.
Thus, \( -3 \le x \le 5 \).

Marking scheme

M1 for factorising to \( (x - 5)(x + 3) \) or finding the critical values \( -3 \) and \( 5 \).
A1 for \( -3 \le x \le 5 \) (allow equivalent interval notation, e.g., \( x \ge -3 \) and \( x \le 5 \)).
Question 17 · Structured Working
2.2 marks
Prove algebraically that the recurring decimal \( 0.4\dot{1}\dot{8} \) can be written as \( \frac{23}{55} \).
Show answer & marking scheme

Worked solution

Let \( x = 0.4181818... \)
Then, multiply by 10 to align the decimal point before the recurring digits:
\( 10x = 4.181818... \) (Equation 1)

Multiply by 1000 to move one full repeating period past the decimal point:
\( 1000x = 418.181818... \) (Equation 2)

Subtract Equation 1 from Equation 2:
\( 1000x - 10x = 418.1818... - 4.1818... \)
\( 990x = 414 \)

Solve for \( x \):
\( x = \frac{414}{990} \)

Simplify the fraction by dividing the numerator and denominator by 18:
\( \frac{414 \div 18}{990 \div 18} = \frac{23}{55} \)

Hence, \( 0.4\dot{1}\dot{8} = \frac{23}{55} \).

Marking scheme

M1 for setting up two appropriate equations that when subtracted eliminate the recurring part (e.g., \( 1000x = 418.\dot{1}\dot{8} \) and \( 10x = 4.\dot{1}\dot{8} \)).
A1 for showing complete steps from \( 990x = 414 \) to the simplified fraction \( \frac{23}{55} \).
Question 18 · Structured Working
2.2 marks
A box contains only red, blue, and green pens.
The ratio of the number of red pens to blue pens is \( 1 : 3 \).
The ratio of the number of blue pens to green pens is \( 9 : 8 \).

Work out the percentage of the pens in the box that are blue.
Show answer & marking scheme

Worked solution

Let the ratio of red to blue be \( R : B = 1 : 3 \).
Let the ratio of blue to green be \( B : G = 9 : 8 \).

To combine these ratios, we make the parts for blue (\( B \)) equal. The lowest common multiple of 3 and 9 is 9.
Multiply the first ratio \( R : B \) by 3:
\( R : B = 3 : 9 \)

Now, we can write the combined ratio:
\( R : B : G = 3 : 9 : 8 \)

Calculate the total number of parts:
\( 3 + 9 + 8 = 20 \) parts

The proportion of blue pens is:
\( \frac{9}{20} \)

Convert this to a percentage:
\( \frac{9}{20} \times 100 = 45\% \)

Marking scheme

M1 for finding a common scale for the ratios to write a combined ratio, e.g., \( R:B:G = 3:9:8 \) (or equivalent).
A1 for \( 45\% \)
Question 19 · Structured Working
2.2 marks
Simplify fully the algebraic fraction:

\( \frac{3x^2 - 14x - 5}{x^2 - 25} \)
Show answer & marking scheme

Worked solution

First, factorise the numerator \( 3x^2 - 14x - 5 \):
We need two numbers that multiply to \( 3 \times (-5) = -15 \) and add to \( -14 \). These numbers are \( -15 \) and \( 1 \).
\( 3x^2 - 15x + x - 5 = 3x(x - 5) + 1(x - 5) = (3x + 1)(x - 5) \)

Next, factorise the denominator \( x^2 - 25 \) using the difference of two squares:
\( x^2 - 25 = (x - 5)(x + 5) \)

Now rewrite the fraction with the factorised terms:
\( \frac{(3x + 1)(x - 5)}{(x - 5)(x + 5)} \)

Cancel the common factor of \( (x - 5) \):
\( \frac{3x + 1}{x + 5} \)

Marking scheme

M1 for factorising either the numerator to \( (3x + 1)(x - 5) \) or the denominator to \( (x - 5)(x + 5) \).
A1 for \( \frac{3x + 1}{x + 5} \)
Question 20 · Structured Working
2.2 marks
A box contains 4 red discs and 6 blue discs.
Two discs are taken at random from the box without replacement.

Work out the probability that the two discs are of different colours. Give your answer as a fraction in its simplest form.
Show answer & marking scheme

Worked solution

The total number of discs is \( 4 + 6 = 10 \).

There are two scenarios where the discs are of different colours:
1. Red then Blue (RB)
2. Blue then Red (BR)

Calculate the probability of Red then Blue:
\( P(\text{Red then Blue}) = \frac{4}{10} \times \frac{6}{9} = \frac{24}{90} \)

Calculate the probability of Blue then Red:
\( P(\text{Blue then Red}) = \frac{6}{10} \times \frac{4}{9} = \frac{24}{90} \)

Sum the two probabilities:
\( P(\text{different colours}) = \frac{24}{90} + \frac{24}{90} = \frac{48}{90} \)

Simplify the fraction by dividing the numerator and denominator by 6:
\( \frac{48 \div 6}{90 \div 6} = \frac{8}{15} \)

Marking scheme

M1 for a correct product for one option, e.g., \( \frac{4}{10} \times \frac{6}{9} \) (or equivalent branch on a tree diagram).
A1 for \( \frac{8}{15} \) (accept equivalent fully simplified fraction).
Question 21 · Structured Working
2.2 marks
A sector of a circle has a radius of \( 9\text{ cm} \) and an angle of \( 120^\circ \).

Work out the perimeter of this sector. Give your answer in the form \( a + b\pi \), where \( a \) and \( b \) are integers.
Show answer & marking scheme

Worked solution

The perimeter of a sector consists of two straight edges (each equal to the radius) and the curved arc length.

Straight edges:
\( 2 \times r = 2 \times 9 = 18\text{ cm} \)

Arc length:
\( \text{Arc length} = \frac{\theta}{360} \times 2\pi r \)
\( \text{Arc length} = \frac{120}{360} \times 2 \times \pi \times 9 \)
\( \text{Arc length} = \frac{1}{3} \times 18\pi = 6\pi\text{ cm} \)

Perimeter:
\( \text{Perimeter} = 18 + 6\pi \)

Marking scheme

M1 for calculating the arc length of the sector, e.g., showing \( \frac{120}{360} \times 2 \times \pi \times 9 \) or obtaining \( 6\pi \).
A1 for \( 18 + 6\pi \) (or equivalent with correct integer values for \( a \) and \( b \)).
Question 22 · Structured Working
2.2 marks
Make \( x \) the subject of the formula:

\( y = \frac{3x - 5}{x + 2} \)
Show answer & marking scheme

Worked solution

Multiply both sides by the denominator \( (x + 2) \):
\( y(x + 2) = 3x - 5 \)

Expand the brackets:
\( xy + 2y = 3x - 5 \)

Rearrange the equation to collect all terms containing \( x \) on one side and terms without \( x \) on the other side:
\( 2y + 5 = 3x - xy \)

Factorise \( x \) from the right-hand side:
\( 2y + 5 = x(3 - y) \)

Divide both sides by \( (3 - y) \) to isolate \( x \):
\( x = \frac{2y + 5}{3 - y} \)

Marking scheme

M1 for multiplying by \( (x+2) \) and expanding correctly to get \( xy + 2y = 3x - 5 \), or for isolating terms in \( x \) on one side and factorising to \( x(3 - y) = 2y + 5 \) (or equivalent).
A1 for \( x = \frac{2y + 5}{3 - y} \) (or equivalent, e.g. \( x = \frac{-2y - 5}{y - 3} \)).
Question 23 · Structured Working / Calculation
2.2 marks
Write \(\frac{7}{16}\) as a percentage.
Show answer & marking scheme

Worked solution

Multiply the fraction by 100 to convert it to a percentage:

\(\frac{7}{16} \times 100 = \frac{700}{16}\)

Simplify by dividing the numerator and denominator by 4:

\(\frac{700 \div 4}{16 \div 4} = \frac{175}{4}\)

Convert \(\frac{175}{4}\) to a decimal by division:

\(175 \div 4 = 43.75\)

Therefore, \(\frac{7}{16} = 43.75\%\).

Marking scheme

M1 for attempt to multiply the fraction by 100 or convert to decimal (e.g. \(7 \div 16\))
A1 for 43.75% (or 43.75)
Question 24 · Structured Working / Calculation
2.2 marks
In a box, the ratio of red counters to blue counters is \(3 : 5\). The ratio of blue counters to green counters is \(4 : 7\).

Find the ratio of red counters to green counters in its simplest form.
Show answer & marking scheme

Worked solution

To compare the ratios directly, make the parts representing blue counters equal in both ratios.

For Red : Blue = \(3 : 5\), multiply both parts by 4:
\(R : B = 12 : 20\)

For Blue : Green = \(4 : 7\), multiply both parts by 5:
\(B : G = 20 : 35\)

Now we can combine them into a single ratio:
\(R : B : G = 12 : 20 : 35\)

Thus, the ratio of red counters to green counters is \(12 : 35\).

Marking scheme

M1 for attempting to find a common value for the blue parts (e.g. multiplying the first ratio by 4 and the second by 5, or equivalent)
A1 for 12 : 35 (accept 12 to 35)
Question 25 · Structured Working / Calculation
2.2 marks
Simplify fully \(\frac{6x^2 - 18x}{3x^2 - 27}\).
Show answer & marking scheme

Worked solution

Factorise both the numerator and the denominator:

Numerator: \(6x^2 - 18x = 6x(x - 3)\)

Denominator: \(3x^2 - 27 = 3(x^2 - 9) = 3(x - 3)(x + 3)\) (using the difference of two squares)

Substitute these back into the fraction:

\(\frac{6x(x - 3)}{3(x - 3)(x + 3)}\)

Divide the numerator and the denominator by their common factors, \(3\) and \(x - 3\):

\(\frac{2x}{x + 3}\).

Marking scheme

M1 for factorising either the numerator as \(6x(x-3)\) or the denominator as \(3(x-3)(x+3)\)
A1 for \(\frac{2x}{x+3}\)
Question 26 · Structured Working / Calculation
2.2 marks
Evaluate \(64^{-\frac{2}{3}}\). Give your answer as a simplified fraction.
Show answer & marking scheme

Worked solution

First, write the negative power as a reciprocal:

\(64^{-\frac{2}{3}} = \frac{1}{64^{\frac{2}{3}}}\)

Next, evaluate the fractional power in the denominator. The cube root of 64 is:

\(\sqrt[3]{64} = 4\)

Then square the result:

\(4^2 = 16\)

So, \(64^{\frac{2}{3}} = 16\).

Therefore, \(64^{-\frac{2}{3}} = \frac{1}{16}\).

Marking scheme

M1 for expressing the term with a positive power as \(\frac{1}{64^{2/3}}\), or for correctly finding the cube root of 64 as 4
A1 for \(\frac{1}{16}\)
Question 27 · Structured Working / Calculation
2.2 marks
A biased 4-sided spinner can land on 1, 2, 3 or 4.

The probabilities of landing on each number are given in the table below.

\(\begin{array}{|c|c|c|c|c|} \hline \text{Number} & 1 & 2 & 3 & 4 \\ \hline \text{Probability} & 0.25 & x & 0.45 & 2x \\ \hline \end{array}\)

Work out the probability of landing on 4.
Show answer & marking scheme

Worked solution

The sum of all probabilities must equal 1:

\(0.25 + x + 0.45 + 2x = 1\)

Combine like terms:

\(0.70 + 3x = 1\)

Subtract 0.70 from both sides:

\(3x = 0.30\)

Divide by 3:

\(x = 0.10\)

The probability of landing on 4 is \(2x\):

\(P(4) = 2 \times 0.10 = 0.2\) (or \(\frac{1}{5}\)).

Marking scheme

M1 for setting up the equation \(0.25 + x + 0.45 + 2x = 1\) and solving to find \(x = 0.1\)
A1 for 0.2 (or equivalent fraction/percentage)
Question 28 · Structured Working / Calculation
2.2 marks
Solve the simultaneous equations:

\(3x + 2y = 4\)

\(4x - 3y = 11\)
Show answer & marking scheme

Worked solution

Multiply the first equation by 3 and the second equation by 2 to align the coefficients of \(y\):

\(9x + 6y = 12\)

\(8x - 6y = 22\)

Add the two equations together:

\(17x = 34\)

\(x = 2\)

Substitute \(x = 2\) back into the first equation:

\(3(2) + 2y = 4\)

\(6 + 2y = 4\)

\(2y = -2\)

\(y = -1\)

So the solution is \(x = 2, y = -1\).

Marking scheme

M1 for a correct method to eliminate one variable (e.g. multiplying both equations to align coefficients and adding/subtracting)
A1 for both \(x = 2\) and \(y = -1\)
Question 29 · Structured Working / Calculation
2.2 marks
A solid cylinder has a radius of \(3\text{ cm}\) and a height of \(8\text{ cm}\).

Calculate the total surface area of the cylinder.

Give your answer in terms of \(\pi\).
Show answer & marking scheme

Worked solution

The formula for the total surface area of a cylinder is:

\(A = 2\pi r^2 + 2\pi r h\)

where \(r = 3\text{ cm}\) and \(h = 8\text{ cm}\).

First, find the combined area of the two circular ends:

\(2 \times ̇\pi \times 3^2 = 18\pi\)

Next, find the curved surface area:

\(2 \times \pi \times 3 \times 8 = 48\pi\)

Add these together to find the total surface area:

\(18\pi + 48\pi = 66\pi\)

So, the total surface area is \(66\pi\text{ cm}^2\).

Marking scheme

M1 for substituting \(r=3\) and \(h=8\) correctly into either \(2\pi r^2\) (giving \(18\pi\)) or \(2\pi r h\) (giving \(48\pi\))
A1 for \(66\pi\) (accept with units \(66\pi\text{ cm}^2\))
Question 30 · Structured Working / Calculation
2.2 marks
The first four terms of a quadratic sequence are:

\(4, \quad 11, \quad 20, \quad 31, \quad \dots\)

Find an expression, in terms of \(n\), for the \(n\)-th term of this sequence.
Show answer & marking scheme

Worked solution

Find the first differences between the terms:

\(11 - 4 = 7\)

\(20 - 11 = 9\)

\(31 - 20 = 11\)

First differences: \(7, 9, 11\)

Find the second differences:

\(9 - 7 = 2\)

\(11 - 9 = 2\)

Since the second difference is \(2\), the coefficient of the \(n^2\) term is \(\frac{2}{2} = 1\).

Subtract \(n^2\) from each term of the original sequence to find the linear part:

For \(n = 1\): \(4 - 1^2 = 3\)

For \(n = 2\): \(11 - 2^2 = 7\)

For \(n = 3\): \(20 - 3^2 = 11\)

For \(n = 4\): \(31 - 4^2 = 15\)

The linear sequence is \(3, 7, 11, 15, \dots\) which has a common difference of \(4\), so its formula is \(4n - 1\).

Combining these parts gives the \(n\)-th term expression:

\(n^2 + 4n - 1\).

Marking scheme

M1 for finding the second difference of 2 and identifying the \(n^2\) term, or for attempting to subtract \(n^2\) from the sequence terms
A1 for \(n^2 + 4n - 1\) (or equivalent)
Question 31 · Structured Working / Calculation
2.2 marks
In a library of 120 books, 27 are sci-fi novels. What percentage of the books are sci-fi novels?
Show answer & marking scheme

Worked solution

To find the percentage, write the number of sci-fi novels as a fraction of the total books: \(\frac{27}{120}\). Simplify the fraction by dividing the numerator and denominator by 3: \(\frac{27}{120} = \frac{9}{40}\). To convert this fraction to a percentage, multiply by 100: \(\frac{9}{40} \times 100 = \frac{900}{40} = \frac{90}{4} = 22.5\%\).

Marking scheme

M1 for setting up the fraction \(\frac{27}{120}\) or simplifying to \(\frac{9}{40}\). A1 for 22.5%.
Question 32 · Structured Working / Calculation
2.2 marks
Expand and simplify \((3x - 2)(2x + 5)\).
Show answer & marking scheme

Worked solution

Multiply each term in the first bracket by each term in the second bracket: \((3x \times 2x) + (3x \times 5) + (-2 \times 2x) + (-2 \times 5) = 6x^2 + 15x - 4x - 10\). Simplify by combining the like terms: \(15x - 4x = 11x\). This gives \(6x^2 + 11x - 10\).

Marking scheme

M1 for expansion of at least three terms correctly (e.g. \(6x^2 + 15x - 4x\) or similar). A1 for fully correct simplified expression \(6x^2 + 11x - 10\).
Question 33 · Structured Working / Calculation
2.2 marks
A cake recipe uses flour, sugar and butter in the ratio \(5 : 3 : 2\). To make a large cake, a total of \(1.5\text{ kg}\) of these ingredients is used. Work out the mass, in grams, of the sugar used.
Show answer & marking scheme

Worked solution

Convert the total mass to grams: \(1.5\text{ kg} = 1500\text{ g}\). Find the total number of parts in the ratio: \(5 + 3 + 2 = 10\text{ parts}\). Calculate the mass of one part: \(1500\text{ g} / 10 = 150\text{ g}\). Sugar corresponds to 3 parts: \(3 \times 150\text{ g} = 450\text{ g}\).

Marking scheme

M1 for converting to grams (1500) and dividing by 10, or for finding 3/10 of 1.5kg (0.45kg). A1 for 450 (or 450g).
Question 34 · Structured Working / Calculation
2.2 marks
Solve the inequality \(5x - 3 > 3x + 8\).
Show answer & marking scheme

Worked solution

Subtract \(3x\) from both sides of the inequality: \(2x - 3 > 8\). Add 3 to both sides of the inequality: \(2x > 11\). Divide both sides by 2: \(x > 5.5\) (or \(x > \frac{11}{2}\)).

Marking scheme

M1 for rearranging terms correctly to get \(2x > 11\) (or equivalent). A1 for \(x > 5.5\) or \(x > 11/2\).
Question 35 · Structured Working / Calculation
2.2 marks
Work out the value of \((4 \times 10^{-5}) \times (8 \times 10^8)\). Give your answer in standard form.
Show answer & marking scheme

Worked solution

Multiply the numbers: \(4 \times 8 = 32\). Multiply the powers of 10: \(10^{-5} \times 10^8 = 10^{-5+8} = 10^3\). Combine them: \(32 \times 10^3\). Convert to standard form: \(32 \times 10^3 = 3.2 \times 10^1 \times 10^3 = 3.2 \times 10^4\).

Marking scheme

M1 for \(32 \times 10^3\) or \(32000\). A1 for \(3.2 \times 10^4\).
Question 36 · Structured Working / Calculation
2.2 marks
The probability that a biased coin lands on Heads is 0.35. The coin is spun 300 times. Work out an estimate for the number of times the coin lands on Heads.
Show answer & marking scheme

Worked solution

To estimate the number of times, multiply the number of spins by the probability of landing on Heads: \(300 \times 0.35 = 3 \times 35 = 105\).

Marking scheme

M1 for showing multiplication \(300 \times 0.35\). A1 for 105.
Question 37 · Structured Working / Calculation
2.2 marks
Find an expression, in terms of \(n\), for the \(n\)-th term of the arithmetic sequence: \(7, 13, 19, 25, \dots\)
Show answer & marking scheme

Worked solution

Find the common difference between consecutive terms: \(13 - 7 = 6\), \(19 - 13 = 6\). Since the difference is 6, the expression starts with \(6n\). For \(n=1\), \(6(1) = 6\). To get the first term of 7, we must add 1. Therefore, the \(n\)-th term is \(6n + 1\).

Marking scheme

M1 for finding a common difference of 6 or writing \(6n\). A1 for \(6n + 1\).
Question 38 · Structured Working / Calculation
2.2 marks
A trapezium has parallel sides of length \(8\text{ cm}\) and \(12\text{ cm}\). The perpendicular height of the trapezium is \(5.5\text{ cm}\). Work out the area of the trapezium.
Show answer & marking scheme

Worked solution

The formula for the area of a trapezium is \(\text{Area} = \frac{1}{2}(a+b)h\), where \(a\) and \(b\) are the parallel sides and \(h\) is the height. Substitute the given values: \(\text{Area} = \frac{1}{2}(8 + 12) \times 5.5 = \frac{1}{2}(20) \times 5.5 = 10 \times 5.5 = 55\text{ cm}^2\).

Marking scheme

M1 for substituting correctly into the formula: \(\frac{1}{2}(8+12) \times 5.5\). A1 for 55.
Question 39 · Structured Working / Calculation
2 marks
Work out \( 2\frac{1}{4} \div 1\frac{3}{8} \) Give your answer as a mixed number in its simplest form.
Show answer & marking scheme

Worked solution

First, convert both mixed numbers to improper fractions: \( 2\frac{1}{4} = \frac{9}{4} \) and \( 1\frac{3}{8} = \frac{11}{8} \). Next, divide the fractions by multiplying by the reciprocal of the second fraction: \( \frac{9}{4} \div \frac{11}{8} = \frac{9}{4} \times \frac{8}{11} = \frac{72}{44} \). Simplify the fraction by dividing the numerator and denominator by 4: \( \frac{18}{11} \). Convert the improper fraction back to a mixed number: \( 1\frac{7}{11} \).

Marking scheme

M1: For converting both mixed numbers to improper fractions, \( \frac{9}{4} \) and \( \frac{11}{8} \), or for multiplying by the reciprocal of their second fraction. A1: For \( 1\frac{7}{11} \) (or equivalent mixed number in its simplest form).
Question 40 · Structured Working / Calculation
2 marks
Solve \( \frac{3x + 1}{2} = 8 - x \)
Show answer & marking scheme

Worked solution

Multiply both sides of the equation by 2 to clear the fraction: \( 3x + 1 = 2(8 - x) \). Expand the bracket on the right-hand side: \( 3x + 1 = 16 - 2x \). Add \( 2x \) to both sides to collect the x terms on one side: \( 5x + 1 = 16 \). Subtract 1 from both sides: \( 5x = 15 \). Divide both sides by 5: \( x = 3 \).

Marking scheme

M1: For a correct first step of multiplying both sides by 2, e.g. \( 3x + 1 = 2(8 - x) \) or \( 3x + 1 = 16 - 2x \). A1: For \( x = 3 \) (or 3).

Paper 2 (Calculator)

Answer all questions in the spaces provided. You may use a calculator.
41 Question · 76 marks
Question 1 · Short Answer
1.5 marks
A metal rod is measured as \(12.4\text{ cm}\) correct to the nearest millimetre. Write down the upper bound of the length of the metal rod.
Show answer & marking scheme

Worked solution

The measurement is correct to the nearest millimetre, which is \(0.1\text{ cm}\). The maximum error is half of this unit, which is \(0.05\text{ cm}\). To find the upper bound, we add this error to the measured value: \(12.4 + 0.05 = 12.45\text{ cm}\).

Marking scheme

M1: For identifying the error interval boundary of \(0.05\text{ cm}\) (or \(0.5\text{ mm}\)) or for showing \(12.4 + 0.05\).
A1: For \(12.45\) (accept with or without units).
Question 2 · Short Answer
1.5 marks
Divide \(£340\) in the ratio \(2 : 3 : 5\). Work out the value of the largest share.
Show answer & marking scheme

Worked solution

First, calculate the total number of parts in the ratio: \(2 + 3 + 5 = 10\). Next, find the value of one part: \(£340 \div 10 = £34\). The largest share consists of \(5\) parts: \(5 \times £34 = £170\).

Marking scheme

M1: For finding the total number of parts (10) and attempting to find the value of one part (\(340 \div 10\)), or for calculating \(340 \times \frac{5}{10}\).
A1: For \(170\) (accept \(£170\)).
Question 3 · Short Answer
1.5 marks
A car depreciates in value by \(12\%\) each year. At the start of 2021, the car was worth \(£15,000\). Calculate the value of the car at the start of 2023.
Show answer & marking scheme

Worked solution

The multiplier for a \(12\%\) depreciation is \(1 - 0.12 = 0.88\). The duration from the start of 2021 to the start of 2023 is \(2\) years. The value of the car after \(2\) years is: \(15000 \times 0.88^2 = 15000 \times 0.7744 = 11616\).

Marking scheme

M1: For a complete method to find the depreciated value after 2 years, e.g. \(15000 \times 0.88^2\) or finding \(15000 \times 0.88 = 13200\) and then \(13200 \times 0.88\).
A1: For \(11616\) (accept \(£11,616\)).
Question 4 · Short Answer
1.5 marks
A biased coin lands on Heads with a probability of \(0.65\). The coin is spun \(300\) times. Work out an estimate for the number of times the coin lands on Heads.
Show answer & marking scheme

Worked solution

To estimate the number of successful outcomes, multiply the total number of trials by the probability of landing on Heads: \(300 \times 0.65 = 195\).

Marking scheme

M1: For the calculation \(300 \times 0.65\).
A1: For \(195\).
Question 5 · Short Answer
1.5 marks
Solve the inequality \(4x - 7 > 15\).
Show answer & marking scheme

Worked solution

First, add \(7\) to both sides of the inequality: \(4x > 22\). Next, divide both sides by \(4\): \(x > \frac{22}{4}\), which simplifies to \(x > 5.5\).

Marking scheme

M1: For a correct first step to isolate the term in \(x\), e.g., \(4x > 22\) or \(4x = 22\).
A1: For \(x > 5.5\) or \(x > \frac{11}{2}\).
Question 6 · Short Answer
1.5 marks
A straight line passes through the points \((2, 5)\) and \((6, 17)\). Work out the gradient of this line.
Show answer & marking scheme

Worked solution

The gradient \(m\) is given by the formula \(m = \frac{y_2 - y_1}{x_2 - x_1}\). Substituting the coordinates gives: \(m = \frac{17 - 5}{6 - 2} = \frac{12}{4} = 3\).

Marking scheme

M1: For substituting the values into the gradient formula, e.g., \(\frac{17-5}{6-2}\) or finding the change in \(y\) (12) and the change in \(x\) (4).
A1: For \(3\).
Question 7 · Short Answer
1.5 marks
Write the number \(0.000045\) in standard form.
Show answer & marking scheme

Worked solution

To write \(0.000045\) in standard form, we move the decimal point \(5\) places to the right to obtain a number between 1 and 10, which is \(4.5\). Since the decimal moved to the right, the index is negative: \(4.5 \times 10^{-5}\).

Marking scheme

M1: For identifying \(4.5\) and a power of 10, e.g., \(4.5 \times 10^k\) where \(k \neq 0\) or showing division by \(100,000\).
A1: For \(4.5 \times 10^{-5}\).
Question 8 · Short Answer
1.5 marks
A sector of a circle has a radius of \(6\text{ cm}\) and an angle of \(120^\circ\). Calculate the area of the sector. Give your answer in terms of \(\pi\).
Show answer & marking scheme

Worked solution

The area of a sector is given by the formula \(\text{Area} = \frac{\theta}{360} \times \pi r^2\). Substituting the given values: \(\text{Area} = \frac{120}{360} \times \pi \times 6^2 = \frac{1}{3} \times 36\pi = 12\pi\).

Marking scheme

M1: For substituting the values into the sector area formula, e.g., \(\frac{120}{360} \times \pi \times 6^2\).
A1: For \(12\pi\) (accept \(12\pi\text{ cm}^2\)).
Question 9 · Short Answer
1.5 marks
A car was bought for \(£15,000\). In the first year, its value decreased by \(12\%\). In the second year, its value decreased by a further \(8\%\) of its value at the end of the first year. Work out the value of the car at the end of the second year.
Show answer & marking scheme

Worked solution

First year value: \(15000 \times (1 - 0.12) = 15000 \times 0.88 = 13200\)
Second year value: \(13200 \times (1 - 0.08) = 13200 \times 0.92 = 12144\).
Therefore, the value of the car at the end of the second year is \(£12,144\).

Marking scheme

M1: For a correct method to find the value after the first year (e.g., \(15000 \times 0.88\) or finding \(13200\)) or for a complete method to find the final value (e.g., \(15000 \times 0.88 \times 0.92\)).
A0.5: For \(12144\).
Question 10 · Short Answer
1.5 marks
A decorative wooden block has a volume of \(240\text{ cm}^3\) and a mass of \(168\text{ g}\). Work out the density of the wood in \(\text{g/cm}^3\).
Show answer & marking scheme

Worked solution

Using the density formula: \(\text{Density} = \frac{\text{Mass}}{\text{Volume}}\).
\(\text{Density} = \frac{168}{240} = 0.7\text{ g/cm}^3\).

Marking scheme

M1: For \(168 \div 240\).
A0.5: For \(0.7\).
Question 11 · Short Answer
1.5 marks
Solve the equation \(\frac{3x - 5}{4} = 5.5\)
Show answer & marking scheme

Worked solution

Multiply both sides by \(4\):
\(3x - 5 = 5.5 \times 4\)
\(3x - 5 = 22\)
Add \(5\) to both sides:
\(3x = 27\)
Divide by \(3\):
\(x = 9\).

Marking scheme

M1: For a correct first step to isolate the numerator, e.g., \(3x - 5 = 22\) or \(\frac{3x}{4} = 6.75\).
A0.5: For \(9\).
Question 12 · Short Answer
1.5 marks
The probability that a biased coin lands on Heads is \(0.65\). The coin is spun \(300\) times. Calculate an estimate for the number of times the coin lands on Tails.
Show answer & marking scheme

Worked solution

First, find the probability of landing on Tails:
\(P(\text{Tails}) = 1 - 0.65 = 0.35\).
Next, calculate the expected number of Tails:
\(300 \times 0.35 = 105\).

Marking scheme

M1: For \((1 - 0.65) \times 300\) or showing \(0.35 \times 300\) or finding \(195\) (expected number of Heads) and subtracting from \(300\).
A0.5: For \(105\).
Question 13 · Structured Working / Calculation
2 marks
A car is purchased for £18,000. It depreciates in value by 12% in the first year, and then by 8% each year after that. Calculate the value of the car after 3 years. Give your answer to the nearest pound.
Show answer & marking scheme

Worked solution

First year depreciation:
\(18000 \times (1 - 0.12) = 18000 \times 0.88 = £15,840\)

Second and third year depreciation (8% per year for 2 years):
\(15840 \times 0.92^2 = 15840 \times 0.8464 = 13407.024\)

To the nearest pound, the value is £13,407.

Marking scheme

M1: For calculating the value after Year 1: \(18000 \times 0.88 = 15840\), or for set up of a correct depreciation calculation such as \(15840 \times 0.92^2\).
A1: For 13407 (or 13407.02).
Question 14 · Structured Working / Calculation
2 marks
Solve the inequality \(5(x - 3) > 2x + 9\).
Show answer & marking scheme

Worked solution

Expand the bracket:
\(5x - 15 > 2x + 9\)

Subtract \(2x\) from both sides:
\(3x - 15 > 9\)

Add 15 to both sides:
\(3x > 24\)

Divide by 3:
\(x > 8\)

Marking scheme

M1: For a correct expansion of the bracket to \(5x - 15\), or for a correct step to collect the \(x\) terms on one side (e.g. \(3x - 15 > 9\)).
A1: For \(x > 8\).
Question 15 · Structured Working / Calculation
2 marks
A biased spinner can land on Red, Blue, or Yellow. The probability of landing on Red is 0.35. The probability of landing on Blue is 0.4. The spinner is spun 250 times. Calculate an estimate for the number of times the spinner lands on Yellow.
Show answer & marking scheme

Worked solution

Find the probability of landing on Yellow:
\(P(\text{Yellow}) = 1 - (0.35 + 0.4) = 1 - 0.75 = 0.25\)

Calculate the expected number of spins landing on Yellow:
\(250 \times 0.25 = 62.5\)

Marking scheme

M1: For finding the probability of Yellow: \(1 - (0.35 + 0.4) = 0.25\) (or for finding expected Red and Blue: \(250 \times 0.75 = 187.5\)).
A1: For 62.5 (accept 62 or 63).
Question 16 · Structured Working / Calculation
2 marks
Factorise fully the quadratic expression \(x^2 + 5x - 24\).
Show answer & marking scheme

Worked solution

We need two numbers that multiply to give \(-24\) and add to give \(5\).
These numbers are \(+8\) and \(-3\).
Therefore, the factorised expression is \((x + 8)(x - 3)\).

Marking scheme

M1: For writing a product of two linear brackets of the form \((x + a)(x + b)\) where \(a \times b = -24\) or \(a + b = 5\).
A1: For \((x + 8)(x - 3)\) (brackets can be in either order).
Question 17 · Structured Working / Calculation
2 marks
A sector of a circle has a radius of 8 cm and an angle of \(135^\circ\). Calculate the area of the sector. Give your answer to 1 decimal place.
Show answer & marking scheme

Worked solution

Area of a sector is given by:
\(\text{Area} = \frac{\theta}{360} \times \pi r^2\)

Substitute the values:
\(\text{Area} = \frac{135}{360} \times \pi \times 8^2\)
\(\text{Area} = \frac{3}{8} \times 64 \times \pi = 24\pi \approx 75.398...\)

To 1 decimal place, the area is 75.4 \(\text{cm}^2\).

Marking scheme

M1: For substituting the values into the correct sector area formula: \(\frac{135}{360} \times \pi \times 8^2\) (or equivalent).
A1: For 75.4 (accept 75.39 to 75.41).
Question 18 · Structured Working / Calculation
2 marks
Work out the size of an interior angle of a regular octagon.
Show answer & marking scheme

Worked solution

An octagon has \(n = 8\) sides.
Method 1: Using exterior angles.
Exterior angle = \(360^\circ \div 8 = 45^\circ\)
Interior angle = \(180^\circ - 45^\circ = 135^\circ\)

Method 2: Using the sum of interior angles.
Sum of interior angles = \((8 - 2) \times 180^\circ = 6 \times 180^\circ = 1080^\circ\)
One interior angle = \(1080^\circ \div 8 = 135^\circ\).

Marking scheme

M1: For a correct method to find either the sum of the interior angles (\((8-2) \times 180\)) or the size of an exterior angle (\(360 \div 8\)).
A1: For 135.
Question 19 · Structured Working / Calculation
2 marks
A number, \(y\), is rounded to 1 decimal place. The result is 7.4. Write down the error interval for \(y\).
Show answer & marking scheme

Worked solution

The lower bound is the smallest value that rounds up to 7.4, which is 7.35.
The upper bound is the smallest value that rounds to 7.5, which is 7.45.
Therefore, the error interval is \(7.35 \le y < 7.45\).

Marking scheme

M1: For identifying either 7.35 or 7.45.
A1: For \(7.35 \le y < 7.45\) (accept equivalent notation or clear identification of the lower and upper bounds).
Question 20 · Structured Working / Calculation
2 marks
In a school of 1200 students, 432 students walk to school. What percentage of the students do not walk to school?
Show answer & marking scheme

Worked solution

Number of students who do not walk to school:
\(1200 - 432 = 768\)

Percentage who do not walk:
\(\frac{768}{1200} \times 100 = 64\%\)

Alternatively, percentage who walk:
\(\frac{432}{1200} \times 100 = 36\%\)
Percentage who do not walk:
\(100\% - 36\% = 64\%\).

Marking scheme

M1: For finding the number of students who do not walk (768) or for calculating the percentage who walk (36%).
A1: For 64.
Question 21 · Structured Working / Calculation
2 marks
Calculate the value of \(\frac{\sqrt{14.8^2 - 6.33}}{3.1 \times 0.45}\). Give your answer to 3 significant figures.
Show answer & marking scheme

Worked solution

First, evaluate the term inside the square root: \(14.8^2 - 6.33 = 219.04 - 6.33 = 212.71\). Next, calculate the square root: \(\sqrt{212.71} \approx 14.58458\). Then, evaluate the denominator: \(3.1 \times 0.45 = 1.395\). Divide the numerator by the denominator: \(\frac{14.58458}{1.395} \approx 10.4549\). Rounding to 3 significant figures gives \(10.5\).

Marking scheme

M1 for showing \(14.58\dots\) or \(1.395\) or an unrounded answer of \(10.45\dots\) or \(\frac{\sqrt{212.71}}{1.395}\)
A1 for \(10.5\)
Question 22 · Structured Working / Calculation
2 marks
A laptop is sold in a sale for \(\pounds 468\). This is a reduction of \(28\%\) on the original price. Calculate the original price of the laptop.
Show answer & marking scheme

Worked solution

The sale price of \(\pounds 468\) represents \(100\% - 28\% = 72\%\) of the original price. To find the original price, divide the sale price by \(0.72\): \(468 \div 0.72 = 650\). Therefore, the original price was \(\pounds 650\).

Marking scheme

M1 for \(468 \div 0.72\) or equating \(72\% = 468\)
A1 for \(650\)
Question 23 · Structured Working / Calculation
2 marks
A metal alloy is made by mixing copper, zinc, and nickel in the ratio \(5 : 3 : 2\) by mass. A block of this alloy has a mass of \(14.5\text{ kg}\). Calculate the mass of zinc in the block.
Show answer & marking scheme

Worked solution

The total number of shares in the ratio is \(5 + 3 + 2 = 10\). One share is equivalent to \(14.5 \div 10 = 1.45\text{ kg}\). Zinc has \(3\) shares, so the mass of zinc is \(3 \times 1.45 = 4.35\text{ kg}\).

Marking scheme

M1 for \(14.5 \div 10\) or \(14.5 \times \frac{3}{10}\)
A1 for \(4.35\)
Question 24 · Structured Working / Calculation
2 marks
Rearrange the formula \(y = \frac{3x - 5}{2}\) to make \(x\) the subject.
Show answer & marking scheme

Worked solution

Multiply both sides by 2 to get \(2y = 3x - 5\). Add 5 to both sides to get \(2y + 5 = 3x\). Divide both sides by 3 to isolate \(x\), giving \(x = \frac{2y + 5}{3}\).

Marking scheme

M1 for correctly multiplying by 2 (\(2y = 3x - 5\)) or adding 5 to both sides divided by 2 (\(y + 2.5 = 1.5x\))
A1 for \(x = \frac{2y + 5}{3}\) or equivalent correct expression
Question 25 · Structured Working / Calculation
2 marks
Expand and simplify \((2x - 3)(x + 4)\).
Show answer & marking scheme

Worked solution

Using the FOIL method or grid method: \(2x \times x = 2x^2\), \(2x \times 4 = 8x\), \(-3 \times x = -3x\), and \(-3 \times 4 = -12\). Combining these terms gives \(2x^2 + 8x - 3x - 12\). Simplifying the middle terms gives \(2x^2 + 5x - 12\).

Marking scheme

M1 for expansion with at least three correct terms from \(2x^2, 8x, -3x, -12\)
A1 for \(2x^2 + 5x - 12\)
Question 26 · Structured Working / Calculation
2 marks
A biased 4-sided spinner can land on A, B, C or D. The table shows the probabilities of landing on A and B. The probability of landing on C is three times the probability of landing on D. Calculate the probability of landing on C.

Probability table: P(A) = 0.25, P(B) = 0.35.
Show answer & marking scheme

Worked solution

The sum of all probabilities is 1. The remaining probability for C and D combined is \(1 - (0.25 + 0.35) = 1 - 0.60 = 0.40\). Let the probability of D be \(x\). Then the probability of C is \(3x\). This means \(3x + x = 0.40\), so \(4x = 0.40\), which gives \(x = 0.10\). Thus, the probability of landing on C is \(3 \times 0.10 = 0.30\).

Marking scheme

M1 for setting up \(1 - (0.25 + 0.35) = 0.4\) and dividing by 4 to find \(x = 0.1\) or equating \(3x + x = 0.4\)
A1 for \(0.3\) or \(0.30\)
Question 27 · Structured Working / Calculation
2 marks
The exterior angle of a regular polygon is \(15^\circ\). Calculate the number of sides of this regular polygon.
Show answer & marking scheme

Worked solution

The sum of the exterior angles of any regular polygon is always \(360^\circ\). To find the number of sides, divide the total sum of the exterior angles by the size of one exterior angle: \(360^\circ \div 15^\circ = 24\). Therefore, the polygon has 24 sides.

Marking scheme

M1 for \(360 \div 15\)
A1 for \(24\)
Question 28 · Structured Working / Calculation
2 marks
A sector of a circle has a radius of \(8\text{ cm}\) and an angle of \(135^\circ\) at the centre. Calculate the area of the sector. Give your answer to 3 significant figures.
Show answer & marking scheme

Worked solution

The area of a sector is given by the formula \(A = \frac{\theta}{360} \times \pi r^2\). Substituting the given values: \(A = \frac{135}{360} \times \pi \times 8^2 = \frac{3}{8} \times 64\pi = 24\pi \approx 75.3982\text{ cm}^2\). Rounding to 3 significant figures gives \(75.4\text{ cm}^2\).

Marking scheme

M1 for \(\frac{135}{360} \times \pi \times 8^2\) or \(24\pi\) or \(75.39...\)
A1 for \(75.4\)
Question 29 · Structured Working
2 marks
A car is bought for \(£24,000\). It depreciates in value by \(12.5\%\) each year. Calculate the value of the car after \(3\) years. Give your answer to the nearest pound.
Show answer & marking scheme

Worked solution

The multiplier for a \(12.5\%\) decrease is \(1 - 0.125 = 0.875\). After \(3\) years, the value is \(24000 \times 0.875^3 = 16078.125\). To the nearest pound, this is \(16078\).

Marking scheme

M1 for \(24000 \times 0.875^3\) or for working step-by-step for \(3\) years. A1 for \(16078\).
Question 30 · Structured Working
2 marks
\(y\) is directly proportional to the square of \(x\). When \(x = 4\), \(y = 72\). Find the value of \(y\) when \(x = 5\).
Show answer & marking scheme

Worked solution

We can write \(y = kx^2\). Substituting \(x = 4\) and \(y = 72\) gives \(72 = k \times 4^2\), so \(16k = 72\) which means \(k = 4.5\). When \(x = 5\), \(y = 4.5 \times 5^2 = 4.5 \times 25 = 112.5\).

Marking scheme

M1 for writing \(y = kx^2\) and finding \(k = 4.5\). A1 for \(112.5\).
Question 31 · Structured Working
2 marks
Solve the quadratic equation \(3x^2 + 8x - 5 = 0\). Give your answers to \(2\) decimal places.
Show answer & marking scheme

Worked solution

Using the quadratic formula \(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\) with \(a = 3\), \(b = 8\), and \(c = -5\): \(x = \frac{-8 \pm \sqrt{8^2 - 4(3)(-5)}}{2(3)} = \frac{-8 \pm \sqrt{124}}{6}\). This gives \(x \approx 0.52\) and \(x \approx -3.19\).

Marking scheme

M1 for correct substitution into the quadratic formula, e.g. \(\frac{-8 \pm \sqrt{8^2 - 4 \times 3 \times (-5)}}{2 \times 3}\). A1 for both \(0.52\) and \(-3.19\).
Question 32 · Structured Working
2 marks
The mean of four numbers is \(14\). When a fifth number is added, the mean of the five numbers becomes \(15.5\). Find the value of the fifth number.
Show answer & marking scheme

Worked solution

The sum of the first four numbers is \(4 \times 14 = 56\). The sum of all five numbers is \(5 \times 15.5 = 77.5\). The fifth number is \(77.5 - 56 = 21.5\).

Marking scheme

M1 for calculating either \(4 \times 14 = 56\) or \(5 \times 15.5 = 77.5\). A1 for \(21.5\).
Question 33 · Structured Working
2 marks
A sector of a circle of radius \(8\text{ cm}\) has an angle of \(135^\circ\). Calculate the area of the sector. Give your answer to \(1\) decimal place.
Show answer & marking scheme

Worked solution

The area of a sector is \(\frac{\theta}{360} \times \pi r^2\). Substituting the values: \(\text{Area} = \frac{135}{360} \times \pi \times 8^2 = 24\pi \approx 75.398\text{ cm}^2\). To \(1\) decimal place, this is \(75.4\).

Marking scheme

M1 for \(\frac{135}{360} \times \pi \times 8^2\). A1 for \(75.4\).
Question 34 · Structured Working
2 marks
Work out the value of \(\frac{4.2 \times 10^7}{1.5 \times 10^{-3}}\). Give your answer in standard form.
Show answer & marking scheme

Worked solution

Dividing the coefficients: \(4.2 \div 1.5 = 2.8\). Subtracting the indices: \(7 - (-3) = 10\). This gives \(2.8 \times 10^{10}\).

Marking scheme

M1 for dividing the coefficients to get \(2.8\) or working out the power of \(10\) as \(10^{10}\). A1 for \(2.8 \times 10^{10}\) (accept \(2.8 * 10^{10}\)).
Question 35 · Structured Working
2 marks
A biased four-sided spinner can land on the numbers \(1\), \(2\), \(3\) or \(4\). The probability of landing on \(1\) is \(0.3\) and on \(2\) is \(0.4\). The probability of landing on \(3\) is twice the probability of landing on \(4\). Calculate the probability of landing on \(3\).
Show answer & marking scheme

Worked solution

Let \(P(4) = x\), then \(P(3) = 2x\). Since the sum of probabilities is \(1\): \(0.3 + 0.4 + 2x + x = 1 \Rightarrow 0.7 + 3x = 1 \Rightarrow 3x = 0.3 \Rightarrow x = 0.1\). Therefore, \(P(3) = 2 \times 0.1 = 0.2\).

Marking scheme

M1 for setting up a correct equation, e.g. \(0.3 + 0.4 + 3x = 1\) or finding that the remaining probability for \(3\) and \(4\) is \(0.3\). A1 for \(0.2\).
Question 36 · Structured Working
2 marks
Rearrange the formula \(v^2 = u^2 + 2as\) to make \(a\) the subject.
Show answer & marking scheme

Worked solution

Subtract \(u^2\) from both sides: \(v^2 - u^2 = 2as\). Divide both sides by \(2s\): \(a = \frac{v^2 - u^2}{2s}\).

Marking scheme

M1 for isolating the \(a\) term, e.g. \(v^2 - u^2 = 2as\). A1 for \(a = \frac{v^2 - u^2}{2s}\) (or equivalent correct rearrangement).
Question 37 · Structured Working / Calculation
2 marks
A car's value depreciates by 12% in the first year, and then by 6% each year after that. If the car's initial cost was £18,500, calculate its value after 3 years. Give your answer to the nearest pound.
Show answer & marking scheme

Worked solution

Value after 1 year: \(18500 \times 0.88 = 16280\). Value after 3 years: \(16280 \times 0.94^2 = 14385.008\). Rounding to the nearest pound gives £14385.

Marking scheme

M1 for \(18500 \times 0.88 \times 0.94^2\) oe, A1 for 14385 (accept 14385.01)
Question 38 · Structured Working / Calculation
2 marks
A sector of a circle has a radius of 8.5 cm and an angle of 72 degrees. Calculate the area of the sector. Give your answer correct to 3 significant figures.
Show answer & marking scheme

Worked solution

Area of a sector = \((\theta / 360) \times \pi \times r^2\). Here, \((72 / 360) \times \pi \times 8.5^2 = 0.2 \times \pi \times 72.25 = 14.45\pi \approx 45.396...\). To 3 significant figures, this is 45.4.

Marking scheme

M1 for \((72 / 360) \times \pi \times 8.5^2\) oe, A1 for 45.4 (accept answers in range 45.39 to 45.41)
Question 39 · Structured Working / Calculation
2 marks
Expand and simplify: \((2x - 3)(3x + 5) - x(x - 4)\)
Show answer & marking scheme

Worked solution

\((2x - 3)(3x + 5) = 6x^2 + 10x - 9x - 15 = 6x^2 + x - 15\). Expanding the second part: \(-x(x - 4) = -x^2 + 4x\). Combining these terms: \(6x^2 + x - 15 - x^2 + 4x = 5x^2 + 5x - 15\).

Marking scheme

M1 for expanding either part with at least 3 terms correct in \((2x - 3)(3x + 5)\) (e.g., \(6x^2 + x - 15\)) or expanding \(-x(x - 4)\) to \(-x^2 + 4x\), A1 for \(5x^2 + 5x - 15\)
Question 40 · Structured Working / Calculation
2 marks
The probability that a biased coin lands on heads is 0.35. The coin is spun 140 times. Work out an estimate for the number of times the coin lands on tails.
Show answer & marking scheme

Worked solution

The probability of landing on tails is \(1 - 0.35 = 0.65\). The expected number of times it lands on tails is \(140 \times 0.65 = 91\).

Marking scheme

M1 for \(1 - 0.35\) or \(140 \times 0.35\) oe, A1 for 91
Question 41 · Structured Working / Calculation
2 marks
A block of metal has a volume of 150 cm^3 and a mass of 1.17 kg. Calculate the density of the metal in g/cm^3.
Show answer & marking scheme

Worked solution

First, convert mass to grams: \(1.17 \text{ kg} = 1170 \text{ g}\). Density = mass / volume = \(1170 / 150 = 7.8 \text{ g/cm}^3\).

Marking scheme

M1 for \(1.17 \times 1000\) or correct division formula e.g. \(1.17 / 150\), A1 for 7.8

Paper 3 (Calculator)

Answer all questions in the spaces provided. You may use a calculator.
41 Question · 76.20000000000002 marks
Question 1 · fill_in
1.4 marks
A fair 3-colour spinner is spun 250 times. The spinner has sections coloured Red, Blue, and Yellow. The probability of landing on Red is 0.34 and the probability of landing on Blue is 0.42. Work out the expected number of times the spinner will land on Yellow.
Show answer & marking scheme

Worked solution

The sum of the probabilities is 1.

The probability of landing on Yellow is:
\(1 - (0.34 + 0.42) = 1 - 0.76 = 0.24\)

The expected number of times the spinner lands on Yellow is:
\(250 \times 0.24 = 60\)

Marking scheme

M1 for finding the probability of Yellow: \(1 - (0.34 + 0.42) = 0.24\)
A1 for multiplying by 250 to get 60
Question 2 · fill_in
1.4 marks
A map has a scale of 1 : 25 000. On the map, the distance between two villages is 8.4 cm. Work out the actual distance between the two villages in kilometres.
Show answer & marking scheme

Worked solution

First, calculate the actual distance in centimetres:
\(8.4 \text{ cm} \times 25\ 000 = 210\ 000 \text{ cm}\)

Convert centimetres to metres by dividing by 100:
\(210\ 000 \div 100 = 2100 \text{ m}\)

Convert metres to kilometres by dividing by 1000:
\(2100 \div 1000 = 2.1 \text{ km}\)

Marking scheme

M1 for \(8.4 \times 25\ 000\) or showing division by 100 000
A1 for 2.1
Question 3 · fill_in
1.4 marks
An investment of £4200 earns compound interest at a rate of 2.3% per annum. Work out the total value of the investment after 3 years. Give your answer to the nearest penny.
Show answer & marking scheme

Worked solution

The interest rate is 2.3% per annum, so the multiplier is \(1 + 0.023 = 1.023\).

The value of the investment after 3 years is:
\(\text{Value} = 4200 \times 1.023^3\)
\(\text{Value} = 4200 \times 1.070599167 \approx 4496.5165...\)

To the nearest penny, this is £4496.52.

Marking scheme

M1 for setting up the calculation \(4200 \times 1.023^3\)
A1 for 4496.52
Question 4 · fill_in
1.4 marks
Solve the inequality \(5x - 7 > 3(x + 2)\).
Show answer & marking scheme

Worked solution

First, expand the brackets:
\(5x - 7 > 3x + 6\)

Subtract \(3x\) from both sides:
\(2x - 7 > 6\)

Add 7 to both sides:
\(2x > 13\)

Divide by 2:
\(x > 6.5\)

Marking scheme

M1 for expanding brackets correctly to \(3x + 6\) and gathering terms on one side, e.g. \(2x > 13\)
A1 for \(x > 6.5\) or \(x > \frac{13}{2}\)
Question 5 · fill_in
1.4 marks
A cylinder has a radius of 4.5 cm and a height of 12 cm. Calculate the volume of the cylinder. Give your answer to 1 decimal place.
Show answer & marking scheme

Worked solution

The formula for the volume of a cylinder is:
\(V = \pi r^2 h\)

Substitute the given values:
\(V = \pi \times 4.5^2 \times 12\)
\(V = \pi \times 20.25 \times 12\)
\(V = 243\pi \approx 763.407... \text{ cm}^3\)

To 1 decimal place, the volume is 763.4 cm\(^3\).

Marking scheme

M1 for \(\pi \times 4.5^2 \times 12\)
A1 for 763.4
Question 6 · fill_in
1.4 marks
Expand and simplify: \((2x - 3)(3x + 5)\)
Show answer & marking scheme

Worked solution

Multiply each term in the first bracket by each term in the second bracket:
\((2x - 3)(3x + 5) = 2x(3x) + 2x(5) - 3(3x) - 3(5)\)
\(= 6x^2 + 10x - 9x - 15\)
\(= 6x^2 + x - 15\)

Marking scheme

M1 for at least 3 correct terms of the quadratic expansion: e.g. \(6x^2\), \(10x\), \(-9x\), \(-15\)
A1 for \(6x^2 + x - 15\)
Question 7 · fill_in
1.4 marks
A metal bar has a mass of 3.4 kg, measured to the nearest 0.1 kg. What is the upper bound of the mass of the metal bar?
Show answer & marking scheme

Worked solution

The measurement is given to the nearest 0.1 kg.

The degree of accuracy is 0.1 kg, so the boundary value is \(0.1 \div 2 = 0.05 \text{ kg}\).

The upper bound is:
\(3.4 + 0.05 = 3.45 \text{ kg}\)

Marking scheme

M1 for identifying the half-unit interval of 0.05
A1 for 3.45
Question 8 · fill_in
1.4 marks
The table shows the heights, \(h\) cm, of 20 plants.

\[\begin{array}{|c|c|}
\hline
\text{Height } (h \text{ cm}) & \text{Frequency} \\
\hline
0 < h \le 10 & 4 \\
10 < h \le 20 & 7 \\
20 < h \le 30 & 9 \\
\hline
\end{array}\]

Calculate an estimate for the mean height of these plants.
Show answer & marking scheme

Worked solution

Find the midpoint (\(x\)) for each interval:
- For \(0 < h \le 10\), midpoint = 5
- For \(10 < h \le 20\), midpoint = 15
- For \(20 < h \le 30\), midpoint = 25

Multiply midpoints by frequencies (\(f \times x\)):
- \(4 \times 5 = 20\)
- \(7 \times 15 = 105\)
- \(9 \times 25 = 225\)

Sum of products = \(20 + 105 + 225 = 350\)
Total frequency = \(4 + 7 + 9 = 20\)

Estimate of the mean = \(350 \div 20 = 17.5\)

Marking scheme

M1 for finding at least two correct midpoints and multiplying by their frequencies, and dividing the sum by 20.
A1 for 17.5
Question 9 · Short Answer
1.4 marks
A car depreciates in value by 8% each year. At the end of 3 years, the car is worth \(£11,679.84\). Work out the original value of the car, in pounds.
Show answer & marking scheme

Worked solution

Let the original value of the car be \(V\).

The multiplier for an 8% depreciation is \(1 - 0.08 = 0.92\).

After 3 years, the value of the car is given by:
\(V \times 0.92^3 = 11,679.84\)

Calculate \(0.92^3\):
\(0.92^3 = 0.778688\)

Now, solve for \(V\):
\(V = \frac{11,679.84}{0.778688} = 15,000\)

Therefore, the original value of the car was \(£15,000\).

Marking scheme

M1: For writing a correct equation involving the depreciation multiplier, e.g. \(V \times 0.92^3 = 11,679.84\), or for evaluating \(0.92^3 = 0.778688\).
A1: For the correct original value of 15000.
Question 10 · Short Answer
1.4 marks
A closed cylinder has a total surface area of \(150\pi\text{ cm}^2\). The radius of the cylinder is \(5\text{ cm\}}. Work out the volume of the cylinder. Give your answer as a multiple of \)\pi\).
Show answer & marking scheme

Worked solution

The formula for the total surface area of a closed cylinder is:
\(A = 2\pi r^2 + 2\pi r h\)

Substitute the given values \(A = 150\pi\) and \(r = 5\):
\(150\pi = 2\pi(5)^2 + 2\pi(5)h\)
\(150\pi = 50\pi + 10\pi h\)

Subtract \(50\pi\) from both sides:
\(100\pi = 10\pi h\)

Divide by \(10\pi\):
\(h = 10\text{ cm}\)

Now, calculate the volume \(V\) of the cylinder using \(V = \pi r^2 h\):
\(V = \pi \times 5^2 \times 10\)
\(V = 250\pi\text{ cm}^3\)

Marking scheme

M1: For setting up a correct equation for the surface area to find the height, e.g. \(150\pi = 50\pi + 10\pi h\), and solving to find \(h = 10\).
A1: For the correct volume of \(250\pi\).
Question 11 · Short Answer
1.4 marks
Solve the simultaneous equations:
\[2x + 3.5y = 15.6\]
\[4.5x - 2y = -0.45\]
Work out the value of \(x + y\).
Show answer & marking scheme

Worked solution

We have the system of equations:
1) \(2x + 3.5y = 15.6\)
2) \(4.5x - 2y = -0.45\)

To eliminate \(y\), multiply equation (1) by 2 and equation (2) by 3.5:
\(4x + 7y = 31.2\)
\(15.75x - 7y = -1.575\)

Add the two equations together:
\(19.75x = 29.625\)

Solve for \(x\):
\(x = \frac{29.625}{19.75} = 1.5\)

Substitute \(x = 1.5\) back into equation (1):
\(2(1.5) + 3.5y = 15.6\)
\(3 + 3.5y = 15.6\)
\(3.5y = 12.6\)
\(y = 3.6\)

Now find \(x + y\):
\(x + y = 1.5 + 3.6 = 5.1\)

Marking scheme

M1: For a complete algebraic method to eliminate one variable to find either \(x = 1.5\) or \(y = 3.6\).
A1: For the correct value of \(5.1\).
Question 12 · Structured Working / Calculation
2.1 marks
A regular polygon has an exterior angle of \(15^\circ\).

Work out the number of sides of this polygon.
Show answer & marking scheme

Worked solution

The sum of the exterior angles of any polygon is \(360^\circ\).

For a regular polygon with \(n\) sides, each exterior angle is \(\frac{360^\circ}{n}\).

So, \(n = \frac{360}{15} = 24\).

Marking scheme

M1 for \(360 \div 15\) or \((n-2) \times 180 = (180 - 15)n\)

A1 for 24
Question 13 · Structured Working / Calculation
2.1 marks
A block of wood has a mass of \(180\text{ g}\) and a volume of \(240\text{ cm}^3\).

Work out the density of the wood. State the units of your answer.
Show answer & marking scheme

Worked solution

Density is calculated by dividing mass by volume:

\(\text{Density} = \frac{\text{Mass}}{\text{Volume}}\)

\(\text{Density} = \frac{180}{240} = 0.75\text{ g/cm}^3\).

Marking scheme

M1 for \(180 \div 240\) or \(0.75\)

A1 for \(0.75\text{ g/cm}^3\) (or equivalent correct units)
Question 14 · Structured Working / Calculation
2.1 marks
In a sale, the price of a coat is reduced by \(15\%\).
The sale price of the coat is \(\text{£}68\).

Work out the original price of the coat.
Show answer & marking scheme

Worked solution

The sale price represents \(100\% - 15\% = 85\%\) of the original price.

Let the original price be \(P\).

\(0.85 \times P = 68\)

\(P = \frac{68}{0.85} = 80\).

So the original price of the coat was \(\text{£}80\).

Marking scheme

M1 for \(68 \div 0.85\) or finding \(1\% = 68 \div 85\) (which is \(0.8\))

A1 for \(\text{£}80\) (accept \(80\))
Question 15 · Structured Working / Calculation
2.1 marks
Solve the inequality

\(5x - 3 > 3x + 8\)
Show answer & marking scheme

Worked solution

First, collect the terms in \(x\) on one side by subtracting \(3x\) from both sides:

\(2x - 3 > 8\)

Next, add \(3\) to both sides:

\(2x > 11\)

Finally, divide both sides by \(2\):

\(x > 5.5\) (or \(x > \frac{11}{2}\))

Marking scheme

M1 for collecting terms in \(x\) on one side and constant terms on the other (e.g. \(2x > 11\) or \(2x = 11\))

A1 for \(x > 5.5\) or \(x > \frac{11}{2}\)
Question 16 · Structured Working / Calculation
2.1 marks
A biased coin is flipped \(150\) times.
It lands on Heads \(93\) times.

Work out the relative frequency of the coin landing on Tails. Give your answer as a decimal.
Show answer & marking scheme

Worked solution

First find the number of times the coin lands on Tails:

\(150 - 93 = 57\)

Then calculate the relative frequency of Tails:

\(\text{Relative frequency} = \frac{57}{150} = 0.38\)

Marking scheme

M1 for \(150 - 93\) (or \(57\)) or \(1 - \frac{93}{150}\)

A1 for \(0.38\)
Question 17 · Structured Working / Calculation
2.1 marks
The mean score of \(5\) students in a test is \(12\).
A sixth student takes the test and the mean score of all \(6\) students becomes \(13\).

Work out the score of the sixth student.
Show answer & marking scheme

Worked solution

Total score of first \(5\) students \(= 5 \times 12 = 60\).

Total score of all \(6\) students \(= 6 \times 13 = 78\).

Score of the sixth student \(= 78 - 60 = 18\).

Marking scheme

M1 for finding the total of either group, e.g. \(5 \times 12 = 60\) or \(6 \times 13 = 78\)

A1 for 18
Question 18 · Structured Working / Calculation
2.1 marks
Here are the first four terms of an arithmetic sequence.

\(7\), \quad \(11\), \quad \(15\), \quad \(19\)

Find an expression, in terms of \(n\), for the \(n\)th term of this sequence.
Show answer & marking scheme

Worked solution

The common difference between terms is \(4\).

So the sequence is related to the \(4n\) times table:

\(4, 8, 12, 16, \dots\)

Each term in our sequence is \(3\) more than the corresponding term of \(4n\).

Therefore, the \(n\)th term is \(4n + 3\).

Marking scheme

M1 for finding a common difference of \(4\) (e.g. \(4n + c\) or showing \(+4\) repeatedly)

A1 for \(4n + 3\) (or equivalent, e.g. \(3 + 4n\))
Question 19 · Structured Working / Calculation
2.1 marks
Expand and simplify

\((x + 3)(x - 5)\)
Show answer & marking scheme

Worked solution

Multiply each term in the first bracket by each term in the second bracket:

\((x + 3)(x - 5) = x^2 - 5x + 3x - 15\)

Combine the like terms (\(-5x + 3x = -2x\)):

\(= x^2 - 2x - 15\)

Marking scheme

M1 for expanding at least 3 terms of the quadratic correctly (e.g. \(x^2 - 5x + 3x\) or \(x^2 - 2x + c\))

A1 for \(x^2 - 2x - 15\)
Question 20 · Structured Working
2 marks
A metal block has a mass of 4.2 kg and a volume of 350 cm³.

Calculate the density of the block in g/cm³.
Show answer & marking scheme

Worked solution

First, convert the mass from kilograms to grams:
\(4.2 \text{ kg} = 4.2 \times 1000 = 4200 \text{ g}\)

Next, use the formula for density:
\(\text{Density} = \frac{\text{Mass}}{\text{Volume}}\)

\(\text{Density} = \frac{4200}{350} = 12 \text{ g/cm}^3\)

Marking scheme

M1 for converting 4.2 kg to 4200 g or for writing \(\frac{4200}{350}\)
A1 for 12
Question 21 · Structured Working
2 marks
A cylinder has a radius of 4.5 cm and a height of 12 cm.

Calculate the volume of the cylinder.
Give your answer to 3 significant figures.
Show answer & marking scheme

Worked solution

The formula for the volume of a cylinder is \(V = \pi r^2 h\).

Substitute the given values into the formula:
\(V = \pi \times 4.5^2 \times 12\)
\(V = \pi \times 20.25 \times 12\)
\(V = 243\pi \approx 763.407... \text{ cm}^3\)

Rounding to 3 significant figures gives 763.

Marking scheme

M1 for \(\pi \times 4.5^2 \times 12\) or \(243\pi\) or \(763.4...\)
A1 for 763
Question 22 · Structured Working
2 marks
Liam invests £3500 in a savings account.
The account pays compound interest at a rate of 2.4% per annum.

Calculate the total amount of interest Liam has earned at the end of 3 years.
Give your answer to the nearest penny.
Show answer & marking scheme

Worked solution

The total amount in the account after 3 years is:
\(3500 \times (1.024)^3 = 3500 \times 1.073741824 = £3758.096384\)

The interest earned is:
\(£3758.096384 - £3500 = £258.096384\)

To the nearest penny, this is £258.10.

Marking scheme

M1 for \(3500 \times 1.024^3\) or \(3758.10\) or \(258.10\)
A1 for 258.10
Question 23 · Structured Working
2 marks
Solve the inequality \(5x - 3 < 3x + 8\)
Show answer & marking scheme

Worked solution

Subtract \(3x\) from both sides:
\(2x - 3 < 8\)

Add 3 to both sides:
\(2x < 11\)

Divide by 2:
\(x < 5.5\) or \(x < \frac{11}{2}\)

Marking scheme

M1 for isolating the x terms on one side, e.g. \(2x < 11\) or \(2x - 3 < 8\) or \(2x = 11\)
A1 for \(x < 5.5\) or \(x < \frac{11}{2}\)
Question 24 · Structured Working
2 marks
Expand and simplify \((2x - 3)(x + 5)\)
Show answer & marking scheme

Worked solution

Multiply each term in the first bracket by each term in the second bracket:
\((2x - 3)(x + 5) = 2x^2 + 10x - 3x - 15\)

Combine like terms:
\(2x^2 + 7x - 15\)

Marking scheme

M1 for expanding to get at least 3 correct terms out of 4 (e.g., \(2x^2 + 10x - 3x - 15\))
A1 for \(2x^2 + 7x - 15\)
Question 25 · Structured Working
2 marks
A group of 20 students took a test.
The mean score of the 12 girls was 74.
The mean score of the 8 boys was 69.

Calculate the mean score of all 20 students.
Show answer & marking scheme

Worked solution

Find the total score of the girls:
\(12 \times 74 = 888\)

Find the total score of the boys:
\(8 \times 69 = 552\)

Find the total score of all students:
\(888 + 552 = 1440\)

Divide by the total number of students:
\(\frac{1440}{20} = 72\)

Marking scheme

M1 for \(12 \times 74\) or \(8 \times 69\) or \(888 + 552\) or \(1440\)
A1 for 72
Question 26 · Structured Working
2 marks
A biased spinner can land on Red, Blue or Yellow.
The probability of landing on Red is 0.4.
The probability of landing on Blue is twice the probability of landing on Yellow.

Calculate the probability of landing on Blue.
Show answer & marking scheme

Worked solution

The sum of all probabilities must be 1:
\(P(\text{Red}) + P(\text{Blue}) + P(\text{Yellow}) = 1\)

Let \(P(\text{Yellow}) = x\), then \(P(\text{Blue}) = 2x\).
\(0.4 + 2x + x = 1\)
\(0.4 + 3x = 1\)
\(3x = 0.6\)
\(x = 0.2\)

Therefore, \(P(\text{Blue}) = 2 \times 0.2 = 0.4\).

Marking scheme

M1 for writing \(0.4 + 2x + x = 1\) or \(3x = 0.6\) or finding \(P(\text{Yellow}) = 0.2\)
A1 for 0.4
Question 27 · Structured Working
2 marks
The sum of the interior angles of a regular polygon is \(1440^\circ\).

Calculate the number of sides of this polygon.
Show answer & marking scheme

Worked solution

The formula for the sum of the interior angles of an \(n\)-sided polygon is:
\(\text{Sum} = (n - 2) \times 180^\circ\)

Set this equal to \(1440^\circ\):
\((n - 2) \times 180 = 1440\)
\(n - 2 = \frac{1440}{180}\)
\(n - 2 = 8\)
\(n = 10\)

Marking scheme

M1 for \((n - 2) \times 180 = 1440\) or \(\frac{1440}{180} + 2\)
A1 for 10
Question 28 · Structured Working / Calculation
2 marks
A machine produces 320 plastic bottles in 8 minutes. How many bottles does the machine produce in 25 minutes?
Show answer & marking scheme

Worked solution

Rate per minute: \(320 \div 8 = 40\) bottles. Bottles produced in 25 minutes: \(40 \times 25 = 1000\).

Marking scheme

M1 for \(320 \div 8\) or showing a correct method to find the rate. A1 for 1000.
Question 29 · Structured Working / Calculation
2 marks
A laptop originally costs \(580\). In a sale, the price is reduced by \(15\%\). Calculate the sale price of the laptop.
Show answer & marking scheme

Worked solution

Calculate 15% of \(580\): \(580 \times 0.15 = 87\). Subtract this from the original price: \(580 - 87 = 493\). Alternatively, \(580 \times 0.85 = 493\).

Marking scheme

M1 for a complete method to find the sale price, e.g. \(580 \times 0.85\) or \(580 - (580 \times 0.15)\). A1 for 493.
Question 30 · Structured Working / Calculation
2 marks
A block of metal has a volume of \(150\text{ cm}^3\) and a mass of \(1.2\text{ kg}\). Calculate the density of the metal in \(\text{g/cm}^3\).
Show answer & marking scheme

Worked solution

Convert mass to grams: \(1.2\text{ kg} = 1200\text{ g}\). Calculate density: \(\text{Density} = \frac{\text{Mass}}{\text{Volume}} = \frac{1200}{150} = 8\text{ g/cm}^3\).

Marking scheme

M1 for converting the mass to grams (1200 g) or writing a correct density division with consistent units. A1 for 8.
Question 31 · Structured Working / Calculation
2 marks
Expand and simplify \(3(2x - 5) - 2(x - 4)\).
Show answer & marking scheme

Worked solution

Expand the terms: \(3(2x - 5) = 6x - 15\) and \(-2(x - 4) = -2x + 8\). Simplify: \(6x - 15 - 2x + 8 = 4x - 7\).

Marking scheme

M1 for expanding at least one bracket correctly to get \(6x - 15\) or \(-2x + 8\). A1 for \(4x - 7\).
Question 32 · Structured Working / Calculation
2 marks
A circle has a radius of \(6.5\text{ cm}\). Calculate the area of the circle. Give your answer to 3 significant figures.
Show answer & marking scheme

Worked solution

Use the formula for the area of a circle: \(\text{Area} = \pi r^2 = \pi \times 6.5^2\). \(\text{Area} = 42.25\pi \approx 132.73\text{ cm}^2\). To 3 significant figures, this rounds to \(133\text{ cm}^2\).

Marking scheme

M1 for substituting \(6.5\) into the area formula: \(\pi \times 6.5^2\) or \(42.25\pi\). A1 for 133 (accept answers in the range 132.7 to 133).
Question 33 · Structured Working / Calculation
2 marks
Work out \((4 \times 10^5) \times (8 \times 10^{-2})\). Give your answer in standard form.
Show answer & marking scheme

Worked solution

Multiply the numbers: \(4 \times 8 = 32\). Multiply the powers of 10: \(10^5 \times 10^{-2} = 10^3\). Combine to get \(32 \times 10^3\). Convert to standard form: \(3.2 \times 10^4\).

Marking scheme

M1 for \(32 \times 10^3\) or \(32000\) or achieving \(3.2 \times 10^n\) where \(n\) is an integer. A1 for \(3.2 \times 10^4\).
Question 34 · Structured Working / Calculation
2 marks
The probability that a biased coin lands on heads is \(0.35\). The coin is spun 200 times. Work out an estimate for the number of times the coin lands on heads.
Show answer & marking scheme

Worked solution

Estimate = \(200 \times 0.35 = 70\).

Marking scheme

M1 for showing the product \(200 \times 0.35\). A1 for 70.
Question 35 · Structured Working / Calculation
2 marks
Solve \(5x - 7 = 2x + 11\).
Show answer & marking scheme

Worked solution

Subtract \(2x\) from both sides: \(3x - 7 = 11\). Add \(7\) to both sides: \(3x = 18\). Divide by \(3\): \(x = 6\).

Marking scheme

M1 for a correct algebraic step to isolate terms in \(x\) on one side and numerical terms on the other, e.g. \(3x - 7 = 11\) or \(5x = 2x + 18\). A1 for 6.
Question 36 · Structured Working / Calculation
2 marks
The price of a coat is £92. The price is first increased by 15%. This new price is then reduced by 20% in a sale.
Calculate the final price of the coat.
Show answer & marking scheme

Worked solution

First, calculate the price after the 15% increase:
\(\text{New Price} = 92 \times 1.15 = 105.80\) pounds.

Next, calculate the price after the 20% reduction:
\(\text{Final Price} = 105.80 \times 0.80 = 84.64\) pounds.

Marking scheme

M1 for finding the price after the 15% increase: \(92 \times 1.15 = 105.80\) (or finding the 15% increase of 13.80), or for a complete multiplier method: \(92 \times 1.15 \times 0.80\)
A1 for 84.64 (or £84.64)
Question 37 · Structured Working / Calculation
2 marks
A cylinder has a radius of 4.5 cm and a volume of \(350\text{ cm}^3\).
Calculate the height of the cylinder. Give your answer to 3 significant figures.
Show answer & marking scheme

Worked solution

The formula for the volume of a cylinder is:
\(V = \pi r^2 h\)

Substitute the given values into the formula:
\(350 = \pi \times 4.5^2 \times h\)
\(350 = 20.25\pi \times h\)

Rearrange to solve for \(h\):
\(h = \frac{350}{20.25\pi} \approx 5.50165\text{ cm}\)

To 3 significant figures, the height is 5.50 cm.

Marking scheme

M1 for a correct substitution into the volume formula, e.g. \(350 = \pi \times 4.5^2 \times h\) or rearranging to make h the subject: \(h = \frac{350}{\pi \times 4.5^2}\)
A1 for 5.50 (accept 5.5)
Question 38 · Structured Working / Calculation
2 marks
Solve the equation:
\(5(2x - 3) = 2(x + 4.5)\)
Show answer & marking scheme

Worked solution

First, expand the brackets on both sides of the equation:
\(10x - 15 = 2x + 9\)

Subtract \(2x\) from both sides:
\(8x - 15 = 9\)

Add 15 to both sides:
\(8x = 24\)

Divide by 8:
\(x = 3\)

Marking scheme

M1 for correctly expanding at least one side, e.g. \(10x - 15\) or \(2x + 9\), or for a correct step in rearranging once expanded (e.g. \(8x = 24\))
A1 for 3
Question 39 · Structured Working / Calculation
2 marks
The table shows information about the number of goals scored by a football team in 25 matches.

| Goals scored | Frequency |
| :--- | :--- |
| 0 | 6 |
| 1 | 8 |
| 2 | 7 |
| 3 | 3 |
| 4 | 1 |

Calculate the mean number of goals scored per match.
Show answer & marking scheme

Worked solution

First, find the total number of goals scored by multiplying each number of goals by its frequency:
\((0 \times 6) + (1 \times 8) + (2 \times 7) + (3 \times 3) + (4 \times 1) = 0 + 8 + 14 + 9 + 4 = 35\)

Next, divide the total number of goals by the total number of matches (25):
\(\text{Mean} = \frac{35}{25} = 1.4\)

Marking scheme

M1 for finding the sum of the goals: \(0 \times 6 + 1 \times 8 + 2 \times 7 + 3 \times 3 + 4 \times 1\) or 35 seen
A1 for 1.4
Question 40 · Structured Working / Calculation
2 marks
A bag contains only red counters and blue counters.
The probability of choosing a red counter at random is 0.35.
There are 26 blue counters in the bag.
Calculate the total number of counters in the bag.
Show answer & marking scheme

Worked solution

The probability of choosing a blue counter is:
\(1 - 0.35 = 0.65\)

Let the total number of counters in the bag be \(N\).
Since the probability of choosing a blue counter is 0.65, we can set up the equation:
\(0.65 \times N = 26\)
\(N = \frac{26}{0.65} = 40\)

Marking scheme

M1 for finding the probability of choosing a blue counter: \(1 - 0.35 = 0.65\) or for setting up the equation \(\frac{26}{N} = 0.65\)
A1 for 40
Question 41 · Structured Working / Calculation
2 marks
A map has a scale of \(1 : 25\\,000\).
The distance between two towns on the map is 8.4 cm.
Calculate the actual distance between the two towns in kilometres.
Show answer & marking scheme

Worked solution

First, calculate the actual distance in centimetres:
\(8.4 \times 25\\,000 = 210\\,000\text{ cm}\)

Next, convert the distance from centimetres to metres (divide by 100):
\(210\\,000 \div 100 = 2100\text{ m}\)

Finally, convert the distance from metres to kilometres (divide by 1000):
\(2100 \div 1000 = 2.1\text{ km}\)

Marking scheme

M1 for \(8.4 \times 25\\,000\) or 210,000 seen, or for a correct conversion method (e.g., dividing by 100,000)
A1 for 2.1

Wondering how well you actually know this?

Thinka is an AI practice app for DSE students — unlimited questions, instant auto-marking, and detailed step-by-step solutions. 100,000+ students use it to confirm they actually know it, not just think they do.

Want more questions like this? Practice unlimited on Thinka — instant answers included.

Start Practising Free