There was an equal number of boys and girls at the canteen. After
49 of the boys and 55 girls left the canteen, there were 15 more boys than girls at the canteen. How many children were there at the canteen at first?
| |
Boys |
Girls |
| Before |
9 u |
9 u |
| Change |
- 4 u |
- 55 |
| After |
5 u |
9 u - 55 |
Number of boys in the end
= 9 u - 4 u
= 5 u
If another 15 girls entered the canteen, the number of boys and girls would be the same.
9 u - 55 + 15 = 5 u
9 u - 40 = 5 u
9 u - 5 u = 40
4 u = 40
1 u = 40 ÷ 4 = 10
Number of children in the canteen at first
= 18 u
= 18 x 10
= 180
Answer(s): 180
