Last week, Tom had a total of 157 white and black files. Two weeks later, he sold
56 of all the white files and 3 black files. Now he has the same number of white and black files. How many files does he have in the end?
|
White |
Black |
Total |
Before |
6 u |
1 u + 3 |
7 u + 3 |
Change |
- 5 u |
- 3 |
|
After |
1 u |
1 u |
|
Comparing the white and black files in the end |
1 |
1 |
|
Total number of files at first
= 6 u + 1 u + 3
= 7 u + 3
7 u + 3 = 157
7 u = 157 - 3
7 u = 154
1 u = 154 ÷ 7 = 22
Number of files that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 22
= 44
Answer(s): 44