At a school, there were 10 boys from Club R and 40% more boys from Club S. Some boys from Club S left and the ratio of the number of boys from Club R to the number of boys from Club S became 5 : 4. How many boys from Club S left?
|
Club R |
Club S |
Before |
10 |
14 |
Change |
|
- ? |
After |
5 u |
4 u |
Number of boys from Club S at first in percent
= 100% + 40%
= 140%
Number of boys from Club S at first
= 140% x 10
=
140100 x 10
= 14
Number of boys in Club R remains unchanged.
5 u = 10
1 u = 10 ÷ 5 = 2
Number of boys from Club S in the end
= 4 u
= 4 x 2
= 8
Number of boys from Club S who left
= 14 - 8
= 6
Answer(s): 6