The number of boys in the canteen was
35 that of the girls. There were 300 more girls than boys. After some girls had left the canteen, the number of boys at the canteen was thrice the number of the remaining girls. How many girls left the canteen?
| |
Girls |
Boys |
Difference |
| Before |
5 u |
3 u |
2 u |
| Change |
- ? |
|
|
| After |
1 u |
3 u |
|
The number of boys at first and in the end remains unchanged.
Number of more girls than boys at first
= 5 u - 3 u
= 2 u
2 u = 300
1 u = 300 ÷ 2 = 150
Number of girls that left
= 5 u - 1 u
= 4 u
= 4 x 150
= 600
Answer(s): 600
