A man rows his boat 78 km downstream and 56 km upstream, taking 4 hours each time. Find the speed of the stream?
Options:
(A) 6
(B) 5
(C) 7
(D) 8
(E) 3 Now, let's think a bit. Some random thoughts:
Speed downstream = d/t = 78/(4) = 20 kmph
Speed upstream = d/t = 56/(4) = 14 kmph
The speed of the stream = (20 - 14)/2 = 3 kmph
The final answer: (E).