A man swims downstream 35 km and upstream 20 km taking 5 hours each time, what is the speed of the man in still water?
Select the correct option.
A) 6.5 B) 5.5 C) 5.2 D) 4.6 E) 9.7
35 --- 5 DS = 7   ? ---- 1   20 ---- 5 US = 4   ? ---- 1 M = ?   M = (7+ 4)/2= 
<gadget id="calculator">(7+ 4)/2</gadget>
<output>11/2 = around 5.5</output>
5.5   Answer: 5.5
<result>B</result>
A man swims downstream 35 km and upstream 20 km taking 5 hours each time, what is the speed of the man in still water?