At a school, there were 10 girls from Club N and 20% more girls from Club P. Some girls from Club P left and the ratio of the number of girls from Club N to the number of girls from Club P became 5 : 4. How many girls from Club P left?
|
Club N |
Club P |
Before |
10 |
12 |
Change |
|
- ? |
After |
5 u |
4 u |
Number of girls from Club P at first in percent
= 100% + 20%
= 120%
Number of girls from Club P at first
= 120% x 10
=
120100 x 10
= 12
Number of girls in Club N remains unchanged.
5 u = 10
1 u = 10 ÷ 5 = 2
Number of girls from Club P in the end
= 4 u
= 4 x 2
= 8
Number of girls from Club P who left
= 12 - 8
= 4
Answer(s): 4