Class 3 Goodness and 3 Peace had the same number of pupils. The ratio of the number of girls in 3 Goodness to the number of girls in 3 Peace was 1 : 9. The ratio of the number of boys in 3 Goodness to the number of boys in 3 Peace was 5 : 1.
- What is the ratio of the number of boys to the number of girls in Class 3 Goodness?
- If there were 21 fewer boys than girls in Class 3 Peace, how many pupils were there each class?
Class 3 Goodness |
Class 3 Peace |
1x11 = 11 u |
1x11 = 11 u |
Girls |
Boys |
Girls |
Boys |
1 |
5x2 |
9 |
1x2 |
1 u |
10 u |
9 u |
2 u |
(a)
Class 3 Goodness
Boys : Girls
1 : 10
(b)
Number of fewer boys than girls in Class 3 Peace
= 9 u - 2 u
= 7 u
7 u = 21
1 u = 21 ÷ 7 = 3
Number of pupils in each class
= 11 u
= 11 x 3
= 33
Answer(s): (a) 1 : 10; (b) 33