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 option:
A) 6
B) 7
C) 5
D) 8
E) 9
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
<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?