At a school, there were 25 children from Club R and 40% less children from Club S. Some children joined Club S and the ratio of the number of children from Club R to the number of children from Club S became 5 : 4. How many children joined Club S?
| |
Club R |
Club S |
| Before |
25 |
15 |
| Change |
|
+ ? |
| After |
5 u |
4 u |
Number of children from Club S at first in percent
= 100% - 40%
= 60%
Number of children from Club S at first
= 60% x 25
=
60100 x 25
= 15
Number of children in Club R remains unchanged.
5 u = 25
1 u = 25 ÷ 5 = 5
Number of children from Club S in the end
= 4 u
= 4 x 5
= 20
Number of children joined Club S
= 20 - 15
= 5
Answer(s): 5
