Let total work to be done = 200 units Work done by A in 50 days =
75
100
×200=500 units A's efficiency =
150
50
=3 units/day Remaining work = 200 - 150 = 50 units Let B's efficiency = x units/day Now, A and B complete remaining work in 10 days ⇒ (3+x)×10=50 ⇒ 3+x=
50
10
=5 ⇒ x=5−3=2 ∴ Time taken by B to complete the whole work alone =