A can do a work in 15 days, B can do it in 10 days. If they work together for 5 days, how much work

A. 1/3

B. 1/4

C. 1/2

D. 1/5

E. None of the above

Answer: C. 1/2

In 5 days, A completes 5/15 = 1/3 and B completes 5/10 = 1/2. Together, they complete 1/3 + 1/2 = 5/6. Thus, 1 - 5/6 = 1/6 of the work is left.

Posted in: Time & Work - Aptitude - Mathematics