There was an equal number of girls and boys at the auditorium. After
35 of the girls and 42 boys left the auditorium, there were 12 more girls than boys at the auditorium. How many children were there at the auditorium at first?
| |
Girls |
Boys |
| Before |
5 u |
5 u |
| Change |
- 3 u |
- 42 |
| After |
2 u |
5 u - 42 |
Number of girls in the end
= 5 u - 3 u
= 2 u
If another 12 boys entered the auditorium, the number of girls and boys would be the same.
5 u - 42 + 12 = 2 u
5 u - 30 = 2 u
5 u - 2 u = 30
3 u = 30
1 u = 30 ÷ 3 = 10
Number of children in the auditorium at first
= 10 u
= 10 x 10
= 100
Answer(s): 100
