At a school, there were 30 boys from Club Z and 40% less boys from Club A. Some boys joined Club A and the ratio of the number of boys from Club Z to the number of boys from Club A became 5 : 4. How many boys joined Club A?
| |
Club Z |
Club A |
| Before |
30 |
18 |
| Change |
|
+ ? |
| After |
5 u |
4 u |
Number of boys from Club A at first in percent
= 100% - 40%
= 60%
Number of boys from Club A at first
= 60% x 30
=
60100 x 30
= 18
Number of boys in Club Z remains unchanged.
5 u = 30
1 u = 30 ÷ 5 = 6
Number of boys from Club A in the end
= 4 u
= 4 x 6
= 24
Number of boys joined Club A
= 24 - 18
= 6
Answer(s): 6
