In May, the ratio of boys and girls in a school's Choir was 3 : 7. In June, 90 new members joined the club. As a result, the ratio of boys to girls in the club became 6 : 5. There were 6 boys in the Choir in May. How many of the new members were girls?
| |
Boys |
Girls |
| Before |
3 u |
7 u |
| Change |
+ 90 |
| After |
6 p |
5 p |
Number of boys at first = 3 u
3 u = 6
1 u = 6 ÷ 3 = 2
Total number of members at first
= 3 u + 7 u
= 10 u
= 10 x 2
= 20
Total number of members in the end
= 20 + 90
= 110
Total number of members in the end
= 6 p + 5 p
= 11 p
11 p = 110
1 p = 110 ÷ 11 = 10
Number of girls in the end
= 5 p
= 5 x 10
= 50
Number of girls at first
= 7 u
= 7 x 2
= 14
Number of new members who were girls
= 50 - 14
= 36
Answer(s): 36
