In November, the ratio of girls and boys in a school's Choir was 5 : 8. In December, 65 new members joined the club. As a result, the ratio of girls to boys in the club became 7 : 6. There were 15 girls in the Choir in November. How many of the new members were boys?
| |
Girls |
Boys |
| Before |
5 u |
8 u |
| Change |
+ 65 |
| After |
7 p |
6 p |
Number of girls at first = 5 u
5 u = 15
1 u = 15 ÷ 5 = 3
Total number of members at first
= 5 u + 8 u
= 13 u
= 13 x 3
= 39
Total number of members in the end
= 39 + 65
= 104
Total number of members in the end
= 7 p + 6 p
= 13 p
13 p = 104
1 p = 104 ÷ 13 = 8
Number of boys in the end
= 6 p
= 6 x 8
= 48
Number of boys at first
= 8 u
= 8 x 3
= 24
Number of new members who were boys
= 48 - 24
= 24
Answer(s): 24
