Bobby and John had 84 files. After Bobby gave 13 files to John. John, in return, gave half of his files to Bobby. In the end, Bobby had twice as many files as John. How many files did Bobby have at first?
| |
Bobby |
John |
Total |
| Before |
1 u + 13 |
2 u - 13 |
84 |
| Change 1 |
- 13 |
+ 13 |
|
| After 1 |
1 u |
2 u |
|
| Change 2 |
+ 1 u |
- 1 u |
|
| After 2 |
2 u |
1 u |
84 |
Total number of files that Bobby and John had at first and in the end remains unchanged.
Total number of files
= 2 u + 1 u
= 3 u
1 u = 84 ÷ 3 = 28
Number of files that Bobby had at first
= 1 u + 13
= 28 + 13
= 41
Answer(s): 41
