At a school, there were 30 children from Club N and 10% more children from Club P. Some children from Club P left and the ratio of the number of children from Club N to the number of children from Club P became 5 : 2. How many children from Club P left?
| |
Club N |
Club P |
| Before |
30 |
33 |
| Change |
|
- ? |
| After |
5 u |
2 u |
Number of children from Club P at first in percent
= 100% + 10%
= 110%
Number of children from Club P at first
= 110% x 30
=
110100 x 30
= 33
Number of children in Club N remains unchanged.
5 u = 30
1 u = 30 ÷ 5 = 6
Number of children from Club P in the end
= 2 u
= 2 x 6
= 12
Number of children from Club P who left
= 33 - 12
= 21
Answer(s): 21
