A can finish a job in 15 hours, B can finish the same job in 10 hours. If they work together for 3 h

A. 1/5

B. 1/3

C. 1/4

D. 1/2

E. None of the above

Answer: B. 1/3

In 3 hours, A and B together complete 3*(1/15 + 1/10) = 1/2 of the job, leaving 1/2 of the job remaining.

Posted in: Time & Work - Aptitude - Mathematics