A man rows his boat 90 km downstream and 72 km upstream, taking 3 hours each time. Find the speed of the stream?\nOptions:\n(A) 6\n(B) 5\n(C) 7\n(D) 3\n(E) 2 Stream of consciousness:
User
Speed downstream = d/t = 90/3 = 30 kmph\nSpeed upstream = d/t = 72/(3) = 24 kmph\nThe speed of the stream = (30 - 24)/2 = 3 kmph
Thus, the answer is (D).
Assistant