At a school, there were 60 boys from Club B and 40% less boys from Club C. Some boys joined Club C and the ratio of the number of boys from Club B to the number of boys from Club C became 5 : 4. How many boys joined Club C?
| |
Club B |
Club C |
| Before |
60 |
36 |
| Change |
|
+ ? |
| After |
5 u |
4 u |
Number of boys from Club C at first in percent
= 100% - 40%
= 60%
Number of boys from Club C at first
= 60% x 60
=
60100 x 60
= 36
Number of boys in Club B remains unchanged.
5 u = 60
1 u = 60 ÷ 5 = 12
Number of boys from Club C in the end
= 4 u
= 4 x 12
= 48
Number of boys joined Club C
= 48 - 36
= 12
Answer(s): 12
