There was an equal number of boys and girls at the school hall. After
29 of the boys and 49 girls left the school hall, there were 11 more boys than girls at the school hall. How many students were there at the school hall at first?
| |
Boys |
Girls |
| Before |
9 u |
9 u |
| Change |
- 2 u |
- 49 |
| After |
7 u |
9 u - 49 |
Number of boys in the end
= 9 u - 2 u
= 7 u
If another 11 girls entered the school hall, the number of boys and girls would be the same.
9 u - 49 + 11 = 7 u
9 u - 38 = 7 u
9 u - 7 u = 38
2 u = 38
1 u = 38 ÷ 2 = 19
Number of students in the school hall at first
= 18 u
= 18 x 19
= 342
Answer(s): 342
