The ratio of the girls to the boys in a kindergarten was 8 : 3. After 23 girls went home and 25 new boys came, there were 7 more girls than boys in the end. Find the number of pupils in the kindergarten in the end.
|
Girls (1) |
Boys (2) |
(3) |
Before |
8 u |
3 u |
3 u |
Change |
- 23 |
+ 25 |
+ 25 + 7 = + 32 |
After |
8 u |
3 u + 25 |
3 u + 32 |
Comparing girls and boys in the end |
7 more |
|
|
Since the number of girls is 7 more than the number of boys in the end, when we
add 7 to (2) to form (3), the number of girls and boys in the end will be the same.
(1) = (3)
8 u - 23 = 3 u + 32
8 u - 3 u = 32 + 23
5 u = 55
1 u = 55 ÷ 5 = 11
Number of pupils in the end
= 8 u + 3 u - 23 + 25
= 11 u + 2
= 11 x 11 + 2
= 121 + 2
= 123
Answer(s): 123