Fractions, Decimals and Percentages: แบบฝึกหัด

Convert the fraction \( \frac{7}{8} \) into a percentage.

In a school of 800 students, \( 35\% \) of them wear glasses. How many students do not wear glasses?

Convert the decimal \( 0.325 \) into a fraction in its simplest form.

If \( 15\% \) of a number is 45, what is the number?

Convert \( 0.125 \) into a fraction in its simplest form and a percentage.

A student scored 18 out of 25 in a test. Express this score as a percentage and find how many more marks are needed to reach \( 80\% \).

The price of a jacket is first increased by \( 20\% \) and then decreased by \( 15\% \) during a sale. If the final price of the jacket is \( \$612 \), find its original price.

A rectangular plot of land has a length of \(24\frac{1}{2}\) meters and a width of \(10.4\) meters.
(a) Express the width as a fraction in its simplest form.
(b) Calculate the area of the plot in square meters, giving your answer as a decimal.

The total price of a laptop is \$8000. A customer pays a deposit of 25% and the remaining balance is paid in 12 equal monthly installments.
(a) Calculate the amount of the deposit.
(b) Calculate the amount of each monthly installment.
(c) If the shop increases the total price by 15%, and the deposit percentage remains 25%, how much more will the new deposit be compared to the original one?