If A and B together can do a piece of work in 20 days, and A alone can do the same work in 30 days, then in how many days can B alone complete the same work?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 60.
Given:
If A and B can do a piece of work together in 20 days,
A alone can do the same work in 30 days
Calculations:
Total work (LCM of 20 and 30) = 60 units
Efficiency of A = 60/30 = 2
Efficiency of A and B = 60/20 = 3
So, the efficiency of B = 3 - 2 = 1
Required number of days = 60/1 = 60 days
Hence, B alone can complete the whole work in 60 days.