One copy machine can make 30 copies a minute, and a second copy machine makes 15 copies a minute. If the two copiers work together, how long would it take them to make 900 copies?\nOptions:\n(A) 15 minutes\n(B) 20 minutes\n(C) 25 minutes\n(D) 30 minutes\n(E) 35 minutes Stream of consciousness first, then make a decision:
User
Total work done by both machines in a minute = 30 + 15 = 45 copies\nTotal number of copies required = 900\nTime = 900/45 = 20 mins
Thus, the answer is (B).
Assistant