At a school, there were 50 pupils from Club A and 30% less pupils from Club B. Some pupils joined Club B and the ratio of the number of pupils from Club A to the number of pupils from Club B became 5 : 4. How many pupils joined Club B?
|
Club A |
Club B |
Before |
50 |
35 |
Change |
|
+ ? |
After |
5 u |
4 u |
Number of pupils from Club B at first in percent
= 100% - 30%
= 70%
Number of pupils from Club B at first
= 70% x 50
=
70100 x 50
= 35
Number of pupils in Club A remains unchanged.
5 u = 50
1 u = 50 ÷ 5 = 10
Number of pupils from Club B in the end
= 4 u
= 4 x 10
= 40
Number of pupils joined Club B
= 40 - 35
= 5
Answer(s): 5