A man rows his boat 105 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Choose the correct choice from the following choices: A) 5 kmph B) 7 kmph C) 12 kmph D) 8 kmph E) 1 kmph
Speed downstream = d/t = 105/(2 1/2) = 42 kmph   Speed upstream = d/t = 45/(2 1/2) = 18 kmph   The speed of the stream = (42 - 18)/2= 
<gadget id="calculator">(42 - 18)/2</gadget>
<output>12</output>
12 kmph   Answer:12 kmph
<result>C</result>
A man rows his boat 105 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?