The ratio of the girls to the boys in a kindergarten was 5 : 3. After 15 girls went home and 21 new boys came, there were 6 more girls than boys in the end. Find the number of students in the kindergarten in the end.
|
Girls (1) |
Boys (2) |
(3) |
Before |
5 u |
3 u |
3 u |
Change |
- 15 |
+ 21 |
+ 21 + 6 = + 27 |
After |
5 u |
3 u + 21 |
3 u + 27 |
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)
5 u - 15 = 3 u + 27
5 u - 3 u = 27 + 15
2 u = 42
1 u = 42 ÷ 2 = 21
Number of students in the end
= 5 u + 3 u - 15 + 21
= 8 u + 6
= 8 x 21 + 6
= 168 + 6
= 174
Answer(s): 174