There was an equal number of boys and girls at the school hall. After
79 of the boys and 59 girls left the school hall, there were 17 more boys than girls at the school hall. How many children were there at the school hall at first?
| |
Boys |
Girls |
| Before |
9 u |
9 u |
| Change |
- 7 u |
- 59 |
| After |
2 u |
9 u - 59 |
Number of boys in the end
= 9 u - 7 u
= 2 u
If another 17 girls entered the school hall, the number of boys and girls would be the same.
9 u - 59 + 17 = 2 u
9 u - 42 = 2 u
9 u - 2 u = 42
7 u = 42
1 u = 42 ÷ 7 = 6
Number of children in the school hall at first
= 18 u
= 18 x 6
= 108
Answer(s): 108
