At a school, there were 25 girls from Club K and 20% more girls from Club L. Some girls from Club L left and the ratio of the number of girls from Club K to the number of girls from Club L became 5 : 4. How many girls from Club L left?
| |
Club K |
Club L |
| Before |
25 |
30 |
| Change |
|
- ? |
| After |
5 u |
4 u |
Number of girls from Club L at first in percent
= 100% + 20%
= 120%
Number of girls from Club L at first
= 120% x 25
=
120100 x 25
= 30
Number of girls in Club K remains unchanged.
5 u = 25
1 u = 25 ÷ 5 = 5
Number of girls from Club L in the end
= 4 u
= 4 x 5
= 20
Number of girls from Club L who left
= 30 - 20
= 10
Answer(s): 10
