Bobby and Liam had 78 files. After Bobby gave 12 files to Liam. Liam, in return, gave half of his files to Bobby. In the end, Bobby had twice as many files as Liam. How many files did Bobby have at first?
| |
Bobby |
Liam |
Total |
| Before |
1 u + 12 |
2 u - 12 |
78 |
| Change 1 |
- 12 |
+ 12 |
|
| After 1 |
1 u |
2 u |
|
| Change 2 |
+ 1 u |
- 1 u |
|
| After 2 |
2 u |
1 u |
78 |
Total number of files that Bobby and Liam had at first and in the end remains unchanged.
Total number of files
= 2 u + 1 u
= 3 u
1 u = 78 ÷ 3 = 26
Number of files that Bobby had at first
= 1 u + 12
= 26 + 12
= 38
Answer(s): 38
