At a school, there were 40 children from Club C and 40% more children from Club D. Some children from Club D left and the ratio of the number of children from Club C to the number of children from Club D became 5 : 2. How many children from Club D left?
|
Club C |
Club D |
Before |
40 |
56 |
Change |
|
- ? |
After |
5 u |
2 u |
Number of children from Club D at first in percent
= 100% + 40%
= 140%
Number of children from Club D at first
= 140% x 40
=
140100 x 40
= 56
Number of children in Club C remains unchanged.
5 u = 40
1 u = 40 ÷ 5 = 8
Number of children from Club D in the end
= 2 u
= 2 x 8
= 16
Number of children from Club D who left
= 56 - 16
= 40
Answer(s): 40