The number of boys in the lecture theatre was
57 that of the girls. There were 110 more girls than boys. After some girls had left the lecture theatre, the number of boys at the lecture theatre was five times the number of the remaining girls. How many girls left the lecture theatre?
|
Girls |
Boys |
Difference |
Before |
7 u |
5 u |
2 u |
Change |
- ? |
|
|
After |
1 u |
5 u |
|
The number of boys at first and in the end remains unchanged.
Number of more girls than boys at first
= 7 u - 5 u
= 2 u
2 u = 110
1 u = 110 ÷ 2 = 55
Number of girls that left
= 7 u - 1 u
= 6 u
= 6 x 55
= 330
Answer(s): 330