In January, the ratio of girls and boys in a school's Badminton Club was 2 : 5. In February, 28 new members joined the club. As a result, the ratio of girls to boys in the club became 4 : 3. There were 8 girls in the Badminton Club in January. 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 = 8
1 u = 8 ÷ 2 = 4
Total number of members at first
= 2 u + 5 u
= 7 u
= 7 x 4
= 28
Total number of members in the end
= 28 + 28
= 56
Total number of members in the end
= 4 p + 3 p
= 7 p
7 p = 56
1 p = 56 ÷ 7 = 8
Number of boys in the end
= 3 p
= 3 x 8
= 24
Number of boys at first
= 5 u
= 5 x 4
= 20
Number of new members who were boys
= 24 - 20
= 4
Answer(s): 4
