Last week, John had a total of 410 green and blue files. Two weeks later, he sold
56 of all the green files and bought another 10 blue files. Now he has the same number of green and blue files. How many files does he have in the end?
| |
Green |
Blue |
Total |
| Before |
6 u |
1 u - 10 |
7 u - 10 |
| Change |
- 5 u |
+ 10 |
|
| After |
1 u |
1 u |
|
Comparing the green
and blue files in the end |
1 |
1 |
|
Total number of files at first
= 6 u + 1 u - 10
= 7 u - 10
7 u - 10 = 410
7 u = 410 + 10
7 u = 420
1 u = 420 ÷ 7 = 60
Number of files that he has in the end
= 1 u + 1 u
= 2 u
= 2 x 60
= 120
Answer(s): 120
