At a school, there were 20 pupils from Club R and 40% less pupils from Club S. Some pupils joined Club S and the ratio of the number of pupils from Club R to the number of pupils from Club S became 4 : 3. How many pupils joined Club S?
| |
Club R |
Club S |
| Before |
20 |
12 |
| Change |
|
+ ? |
| After |
4 u |
3 u |
Number of pupils from Club S at first in percent
= 100% - 40%
= 60%
Number of pupils from Club S at first
= 60% x 20
=
60100 x 20
= 12
Number of pupils in Club R remains unchanged.
4 u = 20
1 u = 20 ÷ 4 = 5
Number of pupils from Club S in the end
= 3 u
= 3 x 5
= 15
Number of pupils joined Club S
= 15 - 12
= 3
Answer(s): 3
