At a school, there were 20 girls from Club A and 10% more girls from Club B. Some girls from Club B left and the ratio of the number of girls from Club A to the number of girls from Club B became 5 : 2. How many girls from Club B left?
| |
Club A |
Club B |
| Before |
20 |
22 |
| Change |
|
- ? |
| After |
5 u |
2 u |
Number of girls from Club B at first in percent
= 100% + 10%
= 110%
Number of girls from Club B at first
= 110% x 20
=
110100 x 20
= 22
Number of girls in Club A remains unchanged.
5 u = 20
1 u = 20 ÷ 5 = 4
Number of girls from Club B in the end
= 2 u
= 2 x 4
= 8
Number of girls from Club B who left
= 22 - 8
= 14
Answer(s): 14
