There was an equal number of girls and boys at the canteen. After
25 of the girls and 47 boys left the canteen, there were 25 more girls than boys at the canteen. How many pupils were there at the canteen at first?
| |
Girls |
Boys |
| Before |
5 u |
5 u |
| Change |
- 2 u |
- 47 |
| After |
3 u |
5 u - 47 |
Number of girls in the end
= 5 u - 2 u
= 3 u
If another 25 boys entered the canteen, the number of girls and boys would be the same.
5 u - 47 + 25 = 3 u
5 u - 22 = 3 u
5 u - 3 u = 22
2 u = 22
1 u = 22 ÷ 2 = 11
Number of pupils in the canteen at first
= 10 u
= 10 x 11
= 110
Answer(s): 110
