Working together, P and Q can do a job in 6 days, Q and R can do the same job in 10 days while P and R can do it in 5 days How long will it take, if all of them work together to complete the job?

Options

A. `4 (2)/(7)` days
B. `4(3)/(7)` days
C. `4(4)/(7)` days
D. `4(5)/(7)` days

Answer

To solve the problem step by step, we will first determine the work done by each pair of workers (P, Q, and R) and then find out how long it will take for all three to complete the job together.

### Step 1: Determine Total Work
Assume the total work to be done is 30 units. This is chosen because it is the least common multiple (LCM) of the days taken by the pairs to complete the work (6, 10, and 5).