At first, there were 411 more boys than girls at the museum. By 4 p.m., a total of 232 boys and girls left the museum. There were as many boys as girls who left the museum. In the end, there were 4 times as many boys as girls who remained behind. How many boys were at the museum at first?
| |
Boys |
Girls |
Difference |
| Before |
4 u + 116 |
1 u + 116 |
411 |
| Change |
- 116 |
- 116 |
|
| After |
4 u |
1 u |
3 u |
Since there was the same number of girls and boys that left, the difference between the number of girls and boys remains unchanged.
3 u = 411
1 u = 411 ÷ 3 = 137
Number of boys in the end
= 4 u
= 4 x 137
= 548
Number of boys that left
= 232 ÷ 2
= 116
Number of boys at first
= 548 + 116
= 664
Answer(s): 664
