Level 2 PSLE
The table shows the number of books read by each child in a class of 21 children. One of the numbers in the table is covered by an ink blot. The average number of books read by the children in the class is 6. What is the number covered by the ink blot?
2 m
Level 3
Some pupils took a Math exam. Their average score was 74.7 marks. One of the pupils' scores was wrongly recorded as 68 marks instead of 86 marks. As a result, the average score was calculated as 73.5 marks. How many pupils sat for the exam?
3 m
Level 3
The average mass of a group of girls was 37 kg. When Jamie, a girl, joined the group, the average mass of the group became 34 kg. If Jamie had a mass of 22 kg, how many girls were there in the group in the end?
3 m
Level 3
The average height of some boys is 145 cm. When 3 girls, with a total height of 393 cm, are included, the average height if the children becomes 142 cm. How many children are there altogether?
3 m
Level 3
Simon has some black and red balls. The total mass of all his balls is 242 g. He has 5 more red balls than black balls. The average mass of the black balls is 6 g. The average mass of the red balls is 10 g. How many balls does Simon have altogether?
3 m
Level 3
Kylie bought some Geography books at $17 each. She also bought an equal number of History books at a different price. The average price of one Geography and one History book was $10. Kylie paid $70 more for the Geography books than the History books.
  1. What was the cost of one History book?
  2. How many Geography books did Kylie buy?
3 m
Level 3
The average mass of a group of girls is 45 kg. If one more girl who weighs 75 kg joins the group, the new average mass of the group will become 48 kg. Find the total number of girls in the group.
3 m
Level 3
The average number of pages Joan read in a certain number of days was 15. In the next four days, Joan read another 88 pages. As a result, the average number of pages she read increased to 17. How many days did Joan read in total?
3 m
Level 3
The average test score of a class was 60 marks. After two students who scored an average marks of 96 marks transferred out of the class, the average score of the remaining students became 58 marks. How many students were there in the class at first?
3 m
Level 3
The average amount of money collected by a group of students at a flag day event was $125. When another 15 students turned up to help, the total amount donated increased by $1275 and the average amount of money collected became $113. How many students were there in the group at first?
3 m