At first, there were 392 more boys than girls at the safari park. By 4 p.m., a total of 240 boys and girls left the safari park. There were as many boys as girls who left the safari park. In the end, there were 5 times as many boys as girls who remained behind. How many boys were at the safari park at first?
|
Boys |
Girls |
Difference |
Before |
5 u + 120 |
1 u + 120 |
392 |
Change |
- 120 |
- 120 |
|
After |
5 u |
1 u |
4 u |
Since there was the same number of girls and boys that left, the difference between the number of girls and boys remains unchanged.
4 u = 392
1 u = 392 ÷ 4 = 98
Number of boys in the end
= 5 u
= 5 x 98
= 490
Number of boys that left
= 240 ÷ 2
= 120
Number of boys at first
= 490 + 120
= 610
Answer(s): 610