A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream? Choose the correct choice:
A) 5 kmph  B) 7 kmph  C) 9 kmph  D) 8 kmph  E) 1 kmph
Speed downstream = d/t = 85/(2 1/2) = 34 kmph   Speed upstream = d/t = 45/(2 1/2) = 18 kmph   The speed of the stream = (34 - 18)/2= 
<gadget id="calculator">(34 - 18)/2</gadget>
<output>8</output>
8 kmph   Answer:8 kmph
<result>D</result>
A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?