Aman can do a piece of work in 78 days. Ram can do this work in 39 days. Aman started the work alone. After how many days should Ram join him, so that the work is finished in 39 days?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 39/2 days.
Aman can do a piece of work in 78 days. Ram can do this work in 39 days.
A's work in 39 days = 39/78 = 1/2 units
Remaining work = 1 - 1/2 = 1/2
Remaining work done by B alone in = 1/2 × 39 = 39/2 days
So, B should join after = 39 - 39/2 = 39/2 days