Class 3 Joy and 3 Faithfulness had the same number of students. The ratio of the number of boys in 3 Joy to the number of boys in 3 Faithfulness was 7 : 13. The ratio of the number of girls in 3 Joy to the number of girls in 3 Faithfulness was 4 : 1.
- What is the ratio of the number of girls to the number of boys in Class 3 Joy?
- If there were 22 fewer girls than boys in Class 3 Faithfulness, how many students were there each class?
Class 3 Joy |
Class 3 Faithfulness |
1x15 = 15 u |
1x15 = 15 u |
Boys |
Girls |
Boys |
Girls |
7 |
4x2 |
13 |
1x2 |
7 u |
8 u |
13 u |
2 u |
(a)
Class 3 Joy
Girls : Boys
7 : 8
(b)
Number of fewer girls than boys in Class 3 Faithfulness
= 13 u - 2 u
= 11 u
11 u = 22
1 u = 22 ÷ 11 = 2
Number of students in each class
= 15 u
= 15 x 2
= 30
Answer(s): (a) 7 : 8; (b) 30