In March, the ratio of boys and girls in a school's Art Club was 5 : 8. In April, 78 new members joined the club. As a result, the ratio of boys to girls in the club became 7 : 6. There were 20 boys in the Art Club in March. How many of the new members were girls?
| |
Boys |
Girls |
| Before |
5 u |
8 u |
| Change |
+ 78 |
| After |
7 p |
6 p |
Number of boys at first = 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Total number of members at first
= 5 u + 8 u
= 13 u
= 13 x 4
= 52
Total number of members in the end
= 52 + 78
= 130
Total number of members in the end
= 7 p + 6 p
= 13 p
13 p = 130
1 p = 130 ÷ 13 = 10
Number of girls in the end
= 6 p
= 6 x 10
= 60
Number of girls at first
= 8 u
= 8 x 4
= 32
Number of new members who were girls
= 60 - 32
= 28
Answer(s): 28
