At a school, there were 40 children from Club J and 25% more children from Club K. Some children from Club K left and the ratio of the number of children from Club J to the number of children from Club K became 4 : 3. How many children from Club K left?
| |
Club J |
Club K |
| Before |
40 |
50 |
| Change |
|
- ? |
| After |
4 u |
3 u |
Number of children from Club K at first in percent
= 100% + 25%
= 125%
Number of children from Club K at first
= 125% x 40
=
125100 x 40
= 50
Number of children in Club J remains unchanged.
4 u = 40
1 u = 40 ÷ 4 = 10
Number of children from Club K in the end
= 3 u
= 3 x 10
= 30
Number of children from Club K who left
= 50 - 30
= 20
Answer(s): 20
