The number of boys in the canteen was
25 that of the girls. There were 171 more girls than boys. After some girls had left the canteen, the number of boys at the canteen was twice the number of the remaining girls. How many girls left the canteen?
| |
Girls |
Boys |
Difference |
| Before |
5 u |
2 u |
3 u |
| Change |
- ? |
|
|
| After |
1 u |
2 u |
|
The number of boys at first and in the end remains unchanged.
Number of more girls than boys at first
= 5 u - 2 u
= 3 u
3 u = 171
1 u = 171 ÷ 3 = 57
Number of girls that left
= 5 u - 1 u
= 4 u
= 4 x 57
= 228
Answer(s): 228
