The speed of a boat in upstream is 80 kmph and the speed of the boat downstream is 120 kmph. Find the speed of the boat in still water and the speed of the stream?  Choose the correct choice from the following:
A) 21 kmph.
B) 22 kmph.
C) 20 kmph.
D) 25 kmph.
E) 28 kmph.
Speed of the boat in still water = (80+120)/2= 
<gadget id="calculator">(80+120)/2</gadget>
<output>100</output>
100 kmph. Speed of the stream= (120-80)/2= 
<gadget id="calculator">(120-80)/2</gadget>
<output>20</output>
20 kmph.   Answer:20 kmph.
<result>C</result>
The speed of a boat in upstream is 80 kmph and the speed of the boat downstream is 120 kmph. Find the speed of the boat in still water and the speed of the stream?