Glen had 5 times as many white files as grey files. After giving away 8 white files and buying another 8 grey files, he had an equal number of white and grey files. How many white files did Glen have at first?
| |
White files |
Grey files |
| Before |
5 u |
1 u |
| Change |
- 8 |
+ 8 |
| After |
5 u - 8 |
1 u + 8 |
The number of white and grey files is the same in the end.
5 u - 8 = 1 u + 8
5 u - 1 u = 8 + 8
4 u = 8 + 8
4 u = 16
1 u = 16 ÷ 4 = 4
Number of white files that Glen had at first
= 5 u
= 5 x 4
= 20
Answer(s): 20
