There was an equal number of girls and boys at the school hall. After
25 of the girls and 48 boys left the school hall, there were 12 more girls than boys at the school hall. How many students were there at the school hall at first?
| |
Girls |
Boys |
| Before |
5 u |
5 u |
| Change |
- 2 u |
- 48 |
| After |
3 u |
5 u - 48 |
Number of girls in the end
= 5 u - 2 u
= 3 u
If another 12 boys entered the school hall, the number of girls and boys would be the same.
5 u - 48 + 12 = 3 u
5 u - 36 = 3 u
5 u - 3 u = 36
2 u = 36
1 u = 36 ÷ 2 = 18
Number of students in the school hall at first
= 10 u
= 10 x 18
= 180
Answer(s): 180
