Student: A can do a piece of work in 3 hours; B and C together can do it in 2 hours, which A and C together can do it in 2 hours. How long will B alone take to do it?\nOptions:\n(A) 6hours\n(B) 3hours\n(C) 2hours\n(D) 5hours\n(E) 4hours.
Another student: Let's say, hmmm...

User
A's 1 hour work = 1/3;\n(B + C)'s 1 hour work = 1/2;\n(A + C)'s 1 hour work = 1/2\n(A + B + C)'s 1 hour work = (1/3 + 1/2) = 5/6\nB's 1 hour work = (5/6 - 1/2) = 1/3\nB alone will take 3 hours to do the work. Final answer: (B).
Assistant