In March, the ratio of girls and boys in a school's Basketball Club was 2 : 5. In April, 80 new members joined the club. As a result, the ratio of girls to boys in the club became 5 : 4. There were 8 girls in the Basketball Club in March. How many of the new members were boys?
| |
Girls |
Boys |
| Before |
2 u |
5 u |
| Change |
+ 80 |
| After |
5 p |
4 p |
Number of girls at first = 2 u
2 u = 8
1 u = 8 ÷ 2 = 4
Total number of members at first
= 2 u + 5 u
= 7 u
= 7 x 4
= 28
Total number of members in the end
= 28 + 80
= 108
Total number of members in the end
= 5 p + 4 p
= 9 p
9 p = 108
1 p = 108 ÷ 9 = 12
Number of boys in the end
= 4 p
= 4 x 12
= 48
Number of boys at first
= 5 u
= 5 x 4
= 20
Number of new members who were boys
= 48 - 20
= 28
Answer(s): 28
