A and B together can complete a work in 3 days. They start together but after 2 days, B left the work. If the work is completed after two more days, B alone could do the work in-

Question: A and B together can complete a work in 3 days. They start together but after 2 days, B left the work. If the work is completed after two more days, B alone could do the work in-

Solution:
(A + B)'s one day's work = 1/3 part
(A + B) works 2 days together = 2/3 part.

∴ Remaining work = 1 - (2/3) = 1/3 part

1/3 part of work is completed by A in two days.
Hence, one day's work of A = 1/6

Then, one day's work of B = (1/3) - (1/6)
= (2 - 1)/6
= 1/6

So, B alone can complete the whole work in 6 days.