The number of girls in the school hall was
35 that of the boys. There were 248 more boys than girls. After some boys had left the school hall, the number of girls at the school hall was thrice the number of the remaining boys. How many boys left the school hall?
| |
Boys |
Girls |
Difference |
| Before |
5 u |
3 u |
2 u |
| Change |
- ? |
|
|
| After |
1 u |
3 u |
|
The number of girls at first and in the end remains unchanged.
Number of more boys than girls at first
= 5 u - 3 u
= 2 u
2 u = 248
1 u = 248 ÷ 2 = 124
Number of boys that left
= 5 u - 1 u
= 4 u
= 4 x 124
= 496
Answer(s): 496
