Give stream of consciousness and then the final answer. A can do a piece of work in 4 hours; B and C together can do it in 3 hours, which A and B together can do it in 2 hours. How long will C alone take to do it?\nOptions:\n(A) 12hours\n(B) 10hours\n(C) 6hours\n(D) 8hours\n(E) 4hours
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A's 1 hour work = 1/4;\n(B + C)'s 1 hour work = 1/3;\n(A + B)'s 1 hour work = 1/2\n(A + B + C)'s 1 hour work = (1/4 + 1/3) = 7/12\nC's 1 hour work = (7/12 - 1/2) = 1/12\nC alone will take 12 hours to do the work.
The final answer: (A).
Assistant