Warren and Bobby had 72 files. After Warren gave 10 files to Bobby. Bobby, in return, gave half of his files to Warren. In the end, Warren had twice as many files as Bobby. How many files did Warren have at first?
| |
Warren |
Bobby |
Total |
| Before |
1 u + 10 |
2 u - 10 |
72 |
| Change 1 |
- 10 |
+ 10 |
|
| After 1 |
1 u |
2 u |
|
| Change 2 |
+ 1 u |
- 1 u |
|
| After 2 |
2 u |
1 u |
72 |
Total number of files that Warren and Bobby had at first and in the end remains unchanged.
Total number of files
= 2 u + 1 u
= 3 u
1 u = 72 ÷ 3 = 24
Number of files that Warren had at first
= 1 u + 10
= 24 + 10
= 34
Answer(s): 34
