P alone can complete a work in 15 days and Q alone can complete the same work in 12 days. They start the work together but after 3 days P leaves the work. How much time will Q take to finish the remaining work?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 6.6 days.
Concept used:
Work done = Time × efficiency
Calculations:
Total work done (LCM of 15 and 12) = 60 units
Efficiency of P = 60/15 = 4
Efficiency of Q = 60/12 = 5
Work done by P and Q in 3 days = (4 + 5) × 3 = 27
Remaining work = 60 - 27 = 33
Time taken by Q to complete the remaining work = 33/5 = 6.6 days