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