A can do a piece of work in 10 days. He works at it for 4 days and then B finishes it in 9 days. In how many days can A and B together finish the work?\nOptions:\n(A) 6\n(B) 8\n(C) 12\n(D) 15\n(E) 20 Stream of consciousness first, then make a decision:
User
4/10+9/X = 1/x = 15\n1/10+1/15 = 1/6 = 6 days
Thus, the answer is (A).
Assistant