There was an equal number of boys and girls at the gymnasium. After
35 of the boys and 52 girls left the gymnasium, there were 13 more boys than girls at the gymnasium. How many children were there at the gymnasium at first?
| |
Boys |
Girls |
| Before |
5 u |
5 u |
| Change |
- 3 u |
- 52 |
| After |
2 u |
5 u - 52 |
Number of boys in the end
= 5 u - 3 u
= 2 u
If another 13 girls entered the gymnasium, the number of boys and girls would be the same.
5 u - 52 + 13 = 2 u
5 u - 39 = 2 u
5 u - 2 u = 39
3 u = 39
1 u = 39 ÷ 3 = 13
Number of children in the gymnasium at first
= 10 u
= 10 x 13
= 130
Answer(s): 130
