For this chain-of-thought reasoning and answer, what was the question?
Speed downstream = d/t = 90/3 = 30 kmph
Speed upstream = d/t = 72/(3) = 24 kmph
The speed of the stream = (30 - 24)/2 = 3 kmph
A: (D)
Q: A man rows his boat 90 km downstream and 72 km upstream, taking 3 hours each time. Find the speed of the stream?
Options:
(A) 6
(B) 5
(C) 7
(D) 3
(E) 2