If A can do a piece of work in 20 days and B can do it in 30 days, how much time will they take to c

A. 12 days

B. 15 days

C. 10 days

D. 18 days

E. None of the above

Answer: B. 15 days

The combined work rate is 1/20 + 1/30 = 1/12. Therefore, they can complete the work together in 12 days.

Posted in: Time & Work - Aptitude - Mathematics