At a school, there were 30 children from Club E and 30% less children from Club F. Some children joined Club F and the ratio of the number of children from Club E to the number of children from Club F became 6 : 5. How many children joined Club F?
| |
Club E |
Club F |
| Before |
30 |
21 |
| Change |
|
+ ? |
| After |
6 u |
5 u |
Number of children from Club F at first in percent
= 100% - 30%
= 70%
Number of children from Club F at first
= 70% x 30
=
70100 x 30
= 21
Number of children in Club E remains unchanged.
6 u = 30
1 u = 30 ÷ 6 = 5
Number of children from Club F in the end
= 5 u
= 5 x 5
= 25
Number of children joined Club F
= 25 - 21
= 4
Answer(s): 4
