At a school, there were 20 girls from Club A and 40% less girls from Club B. Some girls joined Club B and the ratio of the number of girls from Club A to the number of girls from Club B became 4 : 3. How many girls joined Club B?
| |
Club A |
Club B |
| Before |
20 |
12 |
| Change |
|
+ ? |
| After |
4 u |
3 u |
Number of girls from Club B at first in percent
= 100% - 40%
= 60%
Number of girls from Club B at first
= 60% x 20
=
60100 x 20
= 12
Number of girls in Club A remains unchanged.
4 u = 20
1 u = 20 ÷ 4 = 5
Number of girls from Club B in the end
= 3 u
= 3 x 5
= 15
Number of girls joined Club B
= 15 - 12
= 3
Answer(s): 3
