Class 5 Joy and 5 Faithfulness had the same number of students. The ratio of the number of boys in 5 Joy to the number of boys in 5 Faithfulness was 7 : 15. The ratio of the number of girls in 5 Joy to the number of girls in 5 Faithfulness was 5 : 1.
- What is the ratio of the number of girls to the number of boys in Class 5 Joy?
- If there were 39 fewer girls than boys in Class 5 Faithfulness, how many students were there each class?
Class 5 Joy |
Class 5 Faithfulness |
1x17 = 17 u |
1x17 = 17 u |
Boys |
Girls |
Boys |
Girls |
7 |
5x2 |
15 |
1x2 |
7 u |
10 u |
15 u |
2 u |
(a)
Class 5 Joy
Girls : Boys
7 : 10
(b)
Number of fewer girls than boys in Class 5 Faithfulness
= 15 u - 2 u
= 13 u
13 u = 39
1 u = 39 ÷ 13 = 3
Number of students in each class
= 17 u
= 17 x 3
= 51
Answer(s): (a) 7 : 10; (b) 51