A man rows his boat 72 km downstream and 30 km upstream, taking 3 hours each time. Find the speed of the stream?
Choose the correct choice from the following answers.
A) 6 kmph  B) 5 kmph  C) 2 kmph  D) 8 kmph  E) 7 kmph
Speed downstream = d/t = 72/(3)= 
<gadget id="calculator">72/(3)</gadget>
<output>24</output>
24 kmph   Speed upstream= d/t = 30/(3)= 
<gadget id="calculator">30/(3)</gadget>
<output>10</output>
10 kmph   The speed of the stream= (24 - 10)/2= 
<gadget id="calculator">(24 - 10)/2</gadget>
<output>7</output>
7 kmph   Answer:7 kmph
<result>E</result>
A man rows his boat 72 km downstream and 30 km upstream, taking 3 hours each time. Find the speed of the stream?