PSLEBooks in a class library are grouped according to the following four types: Romance, Science, Self-help, and Poetry. 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 Science type?
- There were 22 students in the class. Every student in the class took three or five books home to read over the weekend. No book was left in the classroom. How many students took three books home?
(a)
Total number of books
= 14 + 12 + 41 + 13
= 80
Percentage of books that was Science
=
1280 x 100%
=
320 x 100%
= 15%
(b)
Number of students who took 5 books |
Number of books taken |
Number of students who took 3 books |
Number of books taken |
Total number of books taken |
22 |
22 x 5 = 110 |
0 |
0 |
110 |
21 |
21 x 5 = 105 |
1 |
3 |
108 |
Difference in the number of books taken if 1 more student takes 3 books instead of 5
= 110 - 108
= 2
Total difference in the number of books taken
= 110 - 80
= 30
Number of students who took three books home
= 30 ÷ 2
= 15
Answer(s): (a) 15%; (b) 15