A man rows his boat 90 km downstream and 72 km upstream, taking 3 hours each time. Find the speed of the stream? Choose the correct choice from the following options:
A) 6  B) 5  C) 7  D) 3  E) 2
Speed downstream = d/t = 90/3= 
<gadget id="calculator">90/3</gadget>
<output>30</output>
30 kmph   Speed upstream= d/t = 72/(3)= 
<gadget id="calculator">72/(3)</gadget>
<output>24</output>
24 kmph   The speed of the stream= (30 - 24)/2= 
<gadget id="calculator">(30 - 24)/2</gadget>
<output>3</output>
3 kmph   Answer:3
<result>D</result>
A man rows his boat 90 km downstream and 72 km upstream, taking 3 hours each time. Find the speed of the stream?