Class 3 Patience and 3 Joy had the same number of students. The ratio of the number of girls in 3 Patience to the number of girls in 3 Joy was 1 : 7. The ratio of the number of boys in 3 Patience to the number of boys in 3 Joy was 4 : 1.
- What is the ratio of the number of boys to the number of girls in Class 3 Patience?
- If there were 20 fewer boys than girls in Class 3 Joy, how many students were there each class?
Class 3 Patience |
Class 3 Joy |
1x9 = 9 u |
1x9 = 9 u |
Girls |
Boys |
Girls |
Boys |
1 |
4x2 |
7 |
1x2 |
1 u |
8 u |
7 u |
2 u |
(a)
Class 3 Patience
Boys : Girls
1 : 8
(b)
Number of fewer boys than girls in Class 3 Joy
= 7 u - 2 u
= 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Number of students in each class
= 9 u
= 9 x 4
= 36
Answer(s): (a) 1 : 8; (b) 36