At a school, there were 20 pupils from Club H and 40% less pupils from Club J. Some pupils joined Club J and the ratio of the number of pupils from Club H to the number of pupils from Club J became 5 : 4. How many pupils joined Club J?
| |
Club H |
Club J |
| Before |
20 |
12 |
| Change |
|
+ ? |
| After |
5 u |
4 u |
Number of pupils from Club J at first in percent
= 100% - 40%
= 60%
Number of pupils from Club J at first
= 60% x 20
=
60100 x 20
= 12
Number of pupils in Club H remains unchanged.
5 u = 20
1 u = 20 ÷ 5 = 4
Number of pupils from Club J in the end
= 4 u
= 4 x 4
= 16
Number of pupils joined Club J
= 16 - 12
= 4
Answer(s): 4
