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