There was an equal number of grey and green balls in a box at first. After 27 green balls were taken out and 33 grey balls were added into the box, there was
13 as many green balls as grey balls. Find the number of green balls in the box at first.
|
Grey balls |
Green balls |
Before |
3 u - 33 |
1 u + 27 |
Change |
+ 33 |
- 27 |
After |
3 u |
1 u |
The number of grey and green balls in the box is the same at first.
3 u - 33 = 1 u + 27
3 u - 1 u = 27 + 33
2 u = 60
1 u = 60 ÷ 2 = 30
Number of green balls at first
= 1 u + 27
= 30 + 27
= 57
Answer(s)57