The speed of a boat in upstream is 40 kmph and the speed of the boat downstream is 80 kmph. Find the speed of the boat in still water and the speed of the stream?	Choose the correct choice from the following answers
A) 10 kmph  B) 67 kmph  C) 22 kmph  D) 20 kmph  E) 12 kmph
Speed of the boat in still water   = (40+80)/2= 
<gadget id="calculator">(40+80)/2</gadget>
<output>60</output>
60 kmph. Speed of the stream= (80-40)/2= 
<gadget id="calculator">(80-40)/2</gadget>
<output>20</output>
20 kmph.   Answer:20 kmph
<result>D</result>
The speed of a boat in upstream is 40 kmph and the speed of the boat downstream is 80 kmph. Find the speed of the boat in still water and the speed of the stream?