At a school, there were 12 boys from Club W and 25% more boys from Club X. Some boys from Club X left and the ratio of the number of boys from Club W to the number of boys from Club X became 4 : 3. How many boys from Club X left?
| |
Club W |
Club X |
| Before |
12 |
15 |
| Change |
|
- ? |
| After |
4 u |
3 u |
Number of boys from Club X at first in percent
= 100% + 25%
= 125%
Number of boys from Club X at first
= 125% x 12
=
125100 x 12
= 15
Number of boys in Club W remains unchanged.
4 u = 12
1 u = 12 ÷ 4 = 3
Number of boys from Club X in the end
= 3 u
= 3 x 3
= 9
Number of boys from Club X who left
= 15 - 9
= 6
Answer(s): 6
