A man swims downstream 40 km and upstream 56 km taking 8 hours each time, what is the speed of the man in still water?  Choose the correct choice from the following choices.
A) 6  B) 24  C) 8  D) 12  E) 44
40 --- 8 DS = 5   ? ---- 1   56 ---- 8 US = 7   ? ---- 1 M = ?   M = (5 + 7)/2= 
<gadget id="calculator">(5 + 7)/2</gadget>
<output>6</output>
6   6nswer: 6
<result>A</result>
A man swims downstream 40 km and upstream 56 km taking 8 hours each time, what is the speed of the man in still water?