At a school, there were 30 girls from Club E and 20% more girls from Club F. Some girls from Club F left and the ratio of the number of girls from Club E to the number of girls from Club F became 5 : 3. How many girls from Club F left?
| |
Club E |
Club F |
| Before |
30 |
36 |
| Change |
|
- ? |
| After |
5 u |
3 u |
Number of girls from Club F at first in percent
= 100% + 20%
= 120%
Number of girls from Club F at first
= 120% x 30
=
120100 x 30
= 36
Number of girls in Club E remains unchanged.
5 u = 30
1 u = 30 ÷ 5 = 6
Number of girls from Club F in the end
= 3 u
= 3 x 6
= 18
Number of girls from Club F who left
= 36 - 18
= 18
Answer(s): 18
