P takes twice as long as Q or three times as long as R to complete a task. If they work together, they can complete the task in two days. How long will it take Q to complete the task on his own?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 6 days.
P takes twice as long as Q or three times as long as R to complete a task
The ratio of time taken by P, Q, and R = 3 : 2 : 1
We know that,
Time = 1/Efficiency
Then, the ratio of efficiency of P, Q, and R = 1 : 2 : 3
If they work together, they can complete the task in two days
Total work done in 2 days = 2 × (1 + 2 + 3)
⇒ 2 × 6 = 12 units
Thus, time taken by Q = 12/2 = 6 days