The ratio of the boys to the girls in a kindergarten was 7 : 2. After 22 boys went home and 30 new girls came, there were 8 more boys than girls in the end. Find the number of students in the kindergarten in the end.
|
Boys (1) |
Girls (2) |
(3) |
Before |
7 u |
2 u |
2 u |
Change |
- 22 |
+ 30 |
+ 30 + 8 = + 38 |
After |
7 u |
2 u + 30 |
2 u + 38 |
Comparing boys and girls in the end |
8 more |
|
|
Since the number of boys is 8 more than the number of girls in the end, when we
add 8 to (2) to form (3), the number of boys and girls in the end will be the same.
(1) = (3)
7 u - 22 = 2 u + 38
7 u - 2 u = 38 + 22
5 u = 60
1 u = 60 ÷ 5 = 12
Number of students in the end
= 7 u + 2 u - 22 + 30
= 9 u + 8
= 9 x 12 + 8
= 108 + 8
= 116
Answer(s): 116