A man can row upstream at 10 kmph and downstream at 20 kmph, and then find the speed of the man in still water?
Answers:	A) 11	B) 77	C) 25	D) 88	E) 34
US = 20   DS = 30   M = (30 + 20)/2= 
<gadget id="calculator">(30 + 20)/2</gadget>
<output>25</output>
25   Answer:25
<result>C</result>
A man can row upstream at 10 kmph and downstream at 20 kmph, and then find the speed of the man in still water?