In April, the ratio of boys and girls in a school's Chess Club was 3 : 8. In May, 55 new members joined the club. As a result, the ratio of boys to girls in the club became 6 : 5. There were 9 boys in the Chess Club in April. How many of the new members were girls?
|
Boys |
Girls |
Before |
3 u |
8 u |
Change |
+ 55 |
After |
6 p |
5 p |
Number of boys at first = 3 u
3 u = 9
1 u = 9 ÷ 3 = 3
Total number of members at first
= 3 u + 8 u
= 11 u
= 11 x 3
= 33
Total number of members in the end
= 33 + 55
= 88
Total number of members in the end
= 6 p + 5 p
= 11 p
11 p = 88
1 p = 88 ÷ 11 = 8
Number of girls in the end
= 5 p
= 5 x 8
= 40
Number of girls at first
= 8 u
= 8 x 3
= 24
Number of new members who were girls
= 40 - 24
= 16
Answer(s): 16