In March, the ratio of girls and boys in a school's Chess Club was 2 : 5. In April, 28 new members joined the club. As a result, the ratio of girls to boys in the club became 4 : 3. There were 4 girls in the Chess Club in March. How many of the new members were boys?
| |
Girls |
Boys |
| Before |
2 u |
5 u |
| Change |
+ 28 |
| After |
4 p |
3 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 + 28
= 42
Total number of members in the end
= 4 p + 3 p
= 7 p
7 p = 42
1 p = 42 ÷ 7 = 6
Number of boys in the end
= 3 p
= 3 x 6
= 18
Number of boys at first
= 5 u
= 5 x 2
= 10
Number of new members who were boys
= 18 - 10
= 8
Answer(s): 8
