In April, the ratio of girls and boys in a school's Dance Club was 2 : 5. In May, 85 new members joined the club. As a result, the ratio of girls to boys in the club became 5 : 4. There were 4 girls in the Dance Club in April. How many of the new members were boys?
|
Girls |
Boys |
Before |
2 u |
5 u |
Change |
+ 85 |
After |
5 p |
4 p |
Number of girls at first = 2 u
2 u = 4
1 u = 4 ÷ 2 = 2
Total number of members at first
= 2 u + 5 u
= 7 u
= 7 x 2
= 14
Total number of members in the end
= 14 + 85
= 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 2
= 10
Number of new members who were boys
= 44 - 10
= 34
Answer(s): 34