If two persons A and B works 7 hours a day, then A and B alone can complete a piece of work in 6 days and 8 days respectively. While working 8 hours a day, in what time they would complete it together?
Notes: A alone can complete the work in 42 days working 1 hour daily. Similiarly, B will take 56 days working 1 hour daily.
A’s 1 day’s work
B’s 1 day’s work
(A + B)’s 1 day’s work
∴ Time taken by (A + B) working 8 hours daily 3 days
Hence option [B] is correct answer.