A can do a piece of work in 20 days. B in 15 days A and C in 12 days. In how many days can A finish the work if he is assisted by B on one day and C on the next, alternately?	Pick:	A) 7 days	B) 8 days	C) 5 days	D) 4 days	E) 2 days
A + 8 days = 1/20 + 1/15 = 7/60   A + C = 1/20 + 1/12 = 8/60   7/60 + 8/60 = 15/60 = 1/4   4 days * 2 = 8 days   Answer: 8 days
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A can do a piece of work in 20 days. B in 15 days A and C in 12 days. In how many days can A finish the work if he is assisted by B on one day and C on the next, alternately?