A can do a piece of work in 2 days, and B can do five times the same work in 15 days when they work for ten hours a day. If they work together, then how many hours in addition to a days’ work will they require to complete the work?

2

A = 2 days, x 10 hours = 20

B = 5A = 15 days, B = 3 days,  x 10 hours = 30

⇒ So, A + B will complete the work in = \(\frac{60}{5}\) = 12 days.    ..(\(\frac{Work}{Efficiency}\) = Time )

⇒ So extra time, 12 -10 = 2 hours. 

Therefore, the additional work time will be 2 hours.