At a school, there were 15 students from Club H and 40% less students from Club J. Some students joined Club J and the ratio of the number of students from Club H to the number of students from Club J became 5 : 4. How many students joined Club J?
|
Club H |
Club J |
Before |
15 |
9 |
Change |
|
+ ? |
After |
5 u |
4 u |
Number of students from Club J at first in percent
= 100% - 40%
= 60%
Number of students from Club J at first
= 60% x 15
=
60100 x 15
= 9
Number of students in Club H remains unchanged.
5 u = 15
1 u = 15 ÷ 5 = 3
Number of students from Club J in the end
= 4 u
= 4 x 3
= 12
Number of students joined Club J
= 12 - 9
= 3
Answer(s): 3