At a school, there were 60 boys from Club Z and 30% 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 |
60 |
42 |
| Change |
|
+ ? |
| After |
5 u |
4 u |
Number of boys from Club A at first in percent
= 100% - 30%
= 70%
Number of boys from Club A at first
= 70% x 60
=
70100 x 60
= 42
Number of boys in Club Z remains unchanged.
5 u = 60
1 u = 60 ÷ 5 = 12
Number of boys from Club A in the end
= 4 u
= 4 x 12
= 48
Number of boys joined Club A
= 48 - 42
= 6
Answer(s): 6
