In June, the ratio of girls and boys in a school's Computer Club was 3 : 8. In July, 33 new members joined the club. As a result, the ratio of girls to boys in the club became 6 : 5. There were 12 girls in the Computer Club in June. How many of the new members were boys?
| |
Girls |
Boys |
| Before |
3 u |
8 u |
| Change |
+ 33 |
| After |
6 p |
5 p |
Number of girls at first = 3 u
3 u = 12
1 u = 12 ÷ 3 = 4
Total number of members at first
= 3 u + 8 u
= 11 u
= 11 x 4
= 44
Total number of members in the end
= 44 + 33
= 77
Total number of members in the end
= 6 p + 5 p
= 11 p
11 p = 77
1 p = 77 ÷ 11 = 7
Number of boys in the end
= 5 p
= 5 x 7
= 35
Number of boys at first
= 8 u
= 8 x 4
= 32
Number of new members who were boys
= 35 - 32
= 3
Answer(s): 3
