In July, the ratio of girls and boys in a school's Tennis Club was 3 : 5. In August, 72 new members joined the club. As a result, the ratio of girls to boys in the club became 6 : 5. There were 6 girls in the Tennis Club in July. How many of the new members were boys?
| |
Girls |
Boys |
| Before |
3 u |
5 u |
| Change |
+ 72 |
| After |
6 p |
5 p |
Number of girls at first = 3 u
3 u = 6
1 u = 6 ÷ 3 = 2
Total number of members at first
= 3 u + 5 u
= 8 u
= 8 x 2
= 16
Total number of members in the end
= 16 + 72
= 88
Total number of members in the end
= 6 p + 5 p
= 11 p
11 p = 88
1 p = 88 ÷ 11 = 8
Number of boys in the end
= 5 p
= 5 x 8
= 40
Number of boys at first
= 5 u
= 5 x 2
= 10
Number of new members who were boys
= 40 - 10
= 30
Answer(s): 30
