At a school, there were 50 girls from Club H and 40% less girls from Club J. Some girls joined Club J and the ratio of the number of girls from Club H to the number of girls from Club J became 5 : 4. How many girls joined Club J?
| |
Club H |
Club J |
| Before |
50 |
30 |
| Change |
|
+ ? |
| After |
5 u |
4 u |
Number of girls from Club J at first in percent
= 100% - 40%
= 60%
Number of girls from Club J at first
= 60% x 50
=
60100 x 50
= 30
Number of girls in Club H remains unchanged.
5 u = 50
1 u = 50 ÷ 5 = 10
Number of girls from Club J in the end
= 4 u
= 4 x 10
= 40
Number of girls joined Club J
= 40 - 30
= 10
Answer(s): 10
