The ratio of the girls to the boys in a kindergarten was 7 : 2. After 24 girls went home and 25 new boys came, there were 6 more girls than boys in the end. Find the number of children in the kindergarten in the end.
| |
Girls
(1) |
Boys
(2) |
(3) |
| Before |
7 u |
2 u |
2 u |
| Change |
- 24 |
+ 25 |
+ 25 + 6 = + 31 |
| After |
7 u |
2 u + 25 |
2 u + 31 |
Comparing girls and
boys in the end |
6 more |
|
|
Since the number of girls is 6 more than the number of boys in the end, when we
add 6 to (2) to form (3), the number of girls and boys in the end will be the same.
(1) = (3)
7 u - 24 = 2 u + 31
7 u - 2 u = 31 + 24
5 u = 55
1 u = 55 ÷ 5 = 11
Number of children in the end
= 7 u + 2 u - 24 + 25
= 9 u + 1
= 9 x 11 + 1
= 99 + 1
= 100
Answer(s): 100
