Class 3 Joy and 3 Love had the same number of students. The ratio of the number of girls in 3 Joy to the number of girls in 3 Love was 1 : 7. The ratio of the number of boys in 3 Joy to the number of boys in 3 Love was 3 : 1.
- What is the ratio of the number of boys to the number of girls in Class 3 Joy?
- If there were 12 fewer boys than girls in Class 3 Love, how many students were there each class?
Class 3 Joy |
Class 3 Love |
1x10 = 10 u |
1x10 = 10 u |
Girls |
Boys |
Girls |
Boys |
1 |
3x3 |
7 |
1x3 |
1 u |
9 u |
7 u |
3 u |
(a)
Class 3 Joy
Boys : Girls
1 : 9
(b)
Number of fewer boys than girls in Class 3 Love
= 7 u - 3 u
= 4 u
4 u = 12
1 u = 12 ÷ 4 = 3
Number of students in each class
= 10 u
= 10 x 3
= 30
Answer(s): (a) 1 : 9; (b) 30