P and Q together can complete the work in 20 days. If Q alone can complete the work in 25 days, then in how many days can P alone complete the same work?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 100 days.
Total work = 100 (LCM of 20 and 25)
Efficiency of P = (100/20) - (100/25) = 5 - 4 = 1 unit/day
Time required for P to complete the work = 100/1 = 100 days