問 1
1 点A runner recorded the daily running time for 4 days: \(42\) minutes, \(48\) minutes, \(53\) minutes, and \(57\) minutes.
What was the runner's average daily running time?
Primary School · Mathematics
Averages：練習問題
その場で採点される選択問題 5 問と、解説つきの記述問題 5 問。すべて「Averages」からの出題です。
10 問21 点無料・登録不要
問 2
1 点The average of \(4\) numbers is \(20\). Three of the numbers are \(15, 22,\) and \(18\). What is the fourth number?
問 3
1 点The average age of a group of \(12\) people is \(25\) years. When a new person joins the group, the average age of all the people decreases by \(1\) year. How old is the person who joined the group?
問 4
1 点A bar chart shows the number of books read by four students in a month: Tom read \(5\) books, Mary read \(7\) books, John read \(3\) books, and Lily read \(9\) books. What is the average number of books read by these four students?
問 5
1 点The average height of three plants is \(12.4\text{ cm}\). Two of the plants have heights of \(10.5\text{ cm}\) and \(13.2\text{ cm}\). What is the height of the third plant?
問 6
2 点A runner completed four practice laps in \(68\text{ s}\), \(72\text{ s}\), \(70\text{ s}\), and \(74\text{ s}\). What was his average time per lap in seconds?
まず自分で答えを書いてから、解説と照らし合わせましょう。
問 7
3 点The average score of 5 students in a quiz was $$70$$. After a re-evaluation, one student's score was increased by $$10$$ marks. What is the new average score of the 5 students?
まず自分で答えを書いてから、解説と照らし合わせましょう。
問 8
3 点The average score of $$4$$ quizzes was $$75$$. If a new quiz was taken and the score was $$90$$, what is the new average score for all $$5$$ quizzes?
まず自分で答えを書いてから、解説と照らし合わせましょう。
問 9
4 点The weights of 4 parcels in a delivery van are recorded as follows: \( 3.2\text{ kg} \), \( 4.5\text{ kg} \), \( 3.8\text{ kg} \), and \( 4.1\text{ kg} \).
a) Find the total weight of the 4 parcels.
b) Calculate the average weight of these 4 parcels.
c) If a 5th parcel weighing \( 6.4\text{ kg} \) is added to the van, what is the new total weight of all 5 parcels?
d) What is the new average weight of all 5 parcels?
まず自分で答えを書いてから、解説と照らし合わせましょう。
問 10
4 点A baker prepares pastries. For the first $$3$$ hours, he bakes an average of $$45$$ pastries per hour. In the next $$2$$ hours, he bakes $$30$$ pastries in the first hour and $$50$$ pastries in the second hour. What is the average number of pastries he baked per hour over these $$5$$ hours?
まず自分で答えを書いてから、解説と照らし合わせましょう。
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