PSLEBooks in a class library are grouped according to the following four types: Science, Self-help, History, and Comic. The bar graph shows the number of books of each type in the class library.
- What percentage of books in the class library was of the Self-help type?
- There were 50 pupils in the class. Every pupil in the class took two or four books home to read over the weekend. No book was left in the classroom. How many pupils took two books home?
(a)
Total number of books
= 48 + 21 + 37 + 44
= 150
Percentage of books that was Self-help
=
21150 x 100%
=
750 x 100%
= 14%
(b)
Number of pupils who took 4 books |
Number of books taken |
Number of pupils who took 2 books |
Number of books taken |
Total number of books taken |
50 |
50 x 4 = 200 |
0 |
0 |
200 |
49 |
49 x 4 = 196 |
1 |
2 |
198 |
Difference in the number of books taken if 1 more student takes 2 books instead of 4
= 200 - 198
= 2
Total difference in the number of books taken
= 200 - 150
= 50
Number of pupils who took two books home
= 50 ÷ 2
= 25
Answer(s): (a) 14%; (b) 25