Last week, Fred had a total of 70 brown and gold files. Two weeks later, he sold
23 of all the brown files and 10 gold files. Now he has the same number of brown and gold files. How many files does he have in the end?
| |
Brown |
Gold |
Total |
| Before |
3 u |
1 u + 10 |
4 u + 10 |
| Change |
- 2 u |
- 10 |
|
| After |
1 u |
1 u |
|
Comparing the brown
and gold files in the end |
1 |
1 |
|
Total number of files at first
= 3 u + 1 u + 10
= 4 u + 10
4 u + 10 = 70
4 u = 70 - 10
4 u = 60
1 u = 60 ÷ 4 = 15
Number of files that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 15
= 30
Answer(s): 30
