A can complete a piece of work alone in 120 days, while A and B, working together, can complete this piece of work in 72 days. In how many days can B, working alone, complete this piece of work?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 180.
We know,
Work = Efficiency × time
Now,
Total work (LCM of 120 and 72) = 360 units
⇒ Efficiency of A = 360/120 = 3
⇒ Efficiency of (A + B) = 360/72 = 5
Efficiency of B = 5 - 3 = 2
Hence, the required number of days taken by B to do the work alone = 360/2 = 180