At first, there were 394 more girls than boys at the park. By 4 p.m., a total of 276 girls and boys left the park. There were as many girls as boys who left the park. In the end, there were 3 times as many girls as boys who remained behind. How many girls were at the park at first?
| |
Girls |
Boys |
Difference |
| Before |
3 u + 138 |
1 u + 138 |
394 |
| Change |
- 138 |
- 138 |
|
| After |
3 u |
1 u |
2 u |
Since there was the same number of boys and girls that left, the difference between the number of boys and girls remains unchanged.
2 u = 394
1 u = 394 ÷ 2 = 197
Number of girls in the end
= 3 u
= 3 x 197
= 591
Number of girls that left
= 276 ÷ 2
= 138
Number of girls at first
= 591 + 138
= 729
Answer(s): 729
