A can do a piece of work in 40 days. He works at it for 8 days and B finishes it in 16 days. How long will they take to complete the work if they do it together

A and B working separately can do a piece of work in 8 and 10 hours respectively. If they work for an hour alternately with A beginning, in how many hours will the work be completed

Answer:

A)

B)

C)

D)

Explanation:

Evidently, the work done by A and B during 4 pairs of hours

A can do a piece of work in 25 days, which B alone can finish in 20 days. Both together work for 5 days and then A leaves off. How many days will B take to finish remaining work