There was an equal number of girls and boys at the auditorium. After
58 of the girls and 41 boys left the auditorium, there were 21 more girls than boys at the auditorium. How many pupils were there at the auditorium at first?
| |
Girls |
Boys |
| Before |
8 u |
8 u |
| Change |
- 5 u |
- 41 |
| After |
3 u |
8 u - 41 |
Number of girls in the end
= 8 u - 5 u
= 3 u
If another 21 boys entered the auditorium, the number of girls and boys would be the same.
8 u - 41 + 21 = 3 u
8 u - 20 = 3 u
8 u - 3 u = 20
5 u = 20
1 u = 20 ÷ 5 = 4
Number of pupils in the auditorium at first
= 16 u
= 16 x 4
= 64
Answer(s): 64
