Speed downstream = d/t = 75/(2 1/2) = 28 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (28 - 18)/2 = 5 kmph
A man rows his boat 70 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
  1 kmph
  6 kmph
  5 kmph
  8 kmph
  7 kmph