At a school, there were 15 boys from Club Z and 20% more boys from Club A. Some boys from Club A left and the ratio of the number of boys from Club Z to the number of boys from Club A became 3 : 2. How many boys from Club A left?
| |
Club Z |
Club A |
| Before |
15 |
18 |
| Change |
|
- ? |
| After |
3 u |
2 u |
Number of boys from Club A at first in percent
= 100% + 20%
= 120%
Number of boys from Club A at first
= 120% x 15
=
120100 x 15
= 18
Number of boys in Club Z remains unchanged.
3 u = 15
1 u = 15 ÷ 3 = 5
Number of boys from Club A in the end
= 2 u
= 2 x 5
= 10
Number of boys from Club A who left
= 18 - 10
= 8
Answer(s): 8
