-
A work can be completed by P and Q in 12 days, Q and R in 15 days, R and P in 20 days. In how many days P alone can finish the work?
-
- 10 days
- 20 days
- 30 days
- 60 days
Correct Option: C
| (P + Q)’s 1 day’s work = | .......(i) | 12 |
| (Q + R)’s 1 day’s work = | .......(ii) | 15 |
| (R + P)’s 1 day’s work = | .......(iii) | 20 |
Adding all three equations,
| 2 (P + Q + R)’s 1 day’s work = | + | + | 12 | 15 | 20 |
| 2 (P + Q + R)’s 1 day’s work = | = | 60 | 5 |
| ∴ (P + Q + R)’s 1 day’s work = | .......(iv) | 10 |
| ∴ P’s 1 day’s work = | - | 10 | 15 |
| P’s 1 day’s work = | = | 30 | 30 |
∴ P alone will complete the work in 30 days.
