At a school, there were 20 boys from Club L and 40% less boys from Club M. Some boys joined Club M and the ratio of the number of boys from Club L to the number of boys from Club M became 5 : 4. How many boys joined Club M?
| |
Club L |
Club M |
| Before |
20 |
12 |
| Change |
|
+ ? |
| After |
5 u |
4 u |
Number of boys from Club M at first in percent
= 100% - 40%
= 60%
Number of boys from Club M at first
= 60% x 20
=
60100 x 20
= 12
Number of boys in Club L remains unchanged.
5 u = 20
1 u = 20 ÷ 5 = 4
Number of boys from Club M in the end
= 4 u
= 4 x 4
= 16
Number of boys joined Club M
= 16 - 12
= 4
Answer(s): 4
