The speed of a boat in upstream is 100 kmph and the speed of the boat downstream is 180 kmph. Find the speed of the boat in still water and the speed of the stream?  Select.
A) 10	B) 99	C) 88	D) 40	E) 23
Speed of the boat in still water = (100+180)/2 = 70 kmph. Speed of the stream = (180-100)/2= 
<gadget id="calculator">(180-100)/2</gadget>
<output>40</output>
40 kmph. Answer:40
<result>D</result>
The speed of a boat in upstream is 100 kmph and the speed of the boat downstream is 180 kmph. Find the speed of the boat in still water and the speed of the stream?