A man swims downstream 42 km and upstream 18 km taking 3 hours each time, what is the speed of the man in still water?	Choose the correct choice from the following answers:
A) 2  B) 8  C) 9  D) 6  E) 10
42 --- 3 DS = 14   ? ---- 1   18 ---- 3 US = 6   ? ---- 1 M = ?   M = (14 + 6)/2= 
<gadget id="calculator">(14 + 6)/2</gadget>
<output>10</output>
10   Answer: 10
<result>E</result>
A man swims downstream 42 km and upstream 18 km taking 3 hours each time, what is the speed of the man in still water?