In March, the ratio of girls and boys in a school's Choir was 3 : 5. In April, 59 new members joined the club. As a result, the ratio of girls to boys in the club became 5 : 4. There were 15 girls in the Choir in March. How many of the new members were boys?
| |
Girls |
Boys |
| Before |
3 u |
5 u |
| Change |
+ 59 |
| After |
5 p |
4 p |
Number of girls at first = 3 u
3 u = 15
1 u = 15 ÷ 3 = 5
Total number of members at first
= 3 u + 5 u
= 8 u
= 8 x 5
= 40
Total number of members in the end
= 40 + 59
= 99
Total number of members in the end
= 5 p + 4 p
= 9 p
9 p = 99
1 p = 99 ÷ 9 = 11
Number of boys in the end
= 4 p
= 4 x 11
= 44
Number of boys at first
= 5 u
= 5 x 5
= 25
Number of new members who were boys
= 44 - 25
= 19
Answer(s): 19
