At a school, there were 60 girls from Club C and 10% more girls from Club D. Some girls from Club D left and the ratio of the number of girls from Club C to the number of girls from Club D became 5 : 3. How many girls from Club D left?
| |
Club C |
Club D |
| Before |
60 |
66 |
| Change |
|
- ? |
| After |
5 u |
3 u |
Number of girls from Club D at first in percent
= 100% + 10%
= 110%
Number of girls from Club D at first
= 110% x 60
=
110100 x 60
= 66
Number of girls in Club C remains unchanged.
5 u = 60
1 u = 60 ÷ 5 = 12
Number of girls from Club D in the end
= 3 u
= 3 x 12
= 36
Number of girls from Club D who left
= 66 - 36
= 30
Answer(s): 30
