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A and B can complete a piece of work in 8 days, B and C can do it in 12 days, C and A can do it in 8 days. A, B and C together can complete it in
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- 4 days
- 5 days
- 6 days
- 7 days
Correct Option: C
| (A + B)’s 1 day’s work = | 8 |
| (B + C)’s 1 day’s work = | 12 |
| (C + A)’s 1 day’s work = | 8 |
On adding ,
| 2 (A + B + C)’s 1 day’s work = | + | + | 8 | 12 | 8 |
| 2 (A + B + C)’s 1 day’s work = | 24 |
| 2 (A + B + C)’s 1 day’s work = | = | 24 | 3 |
| ∴ (A + B + C)’s 1 day’s work = | 6 |
Hence, the work will be completed in 6 days.
2nd Method to solve this question :
| Time = | xy + yz + zx |
Here, x = 8, y = 12; z = 8
| Time = | = | = 6 days | 96 + 96 + 64 | 256 |
