There was an equal number of boys and girls at the gymnasium. After
37 of the boys and 34 girls left the gymnasium, there were 25 more boys than girls at the gymnasium. How many pupils were there at the gymnasium at first?
| |
Boys |
Girls |
| Before |
7 u |
7 u |
| Change |
- 3 u |
- 34 |
| After |
4 u |
7 u - 34 |
Number of boys in the end
= 7 u - 3 u
= 4 u
If another 25 girls entered the gymnasium, the number of boys and girls would be the same.
7 u - 34 + 25 = 4 u
7 u - 9 = 4 u
7 u - 4 u = 9
3 u = 9
1 u = 9 ÷ 3 = 3
Number of pupils in the gymnasium at first
= 14 u
= 14 x 3
= 42
Answer(s): 42
