A man swims downstream 36 km and upstream 48 km taking 6 hours each time, what is the speed of the man in still water?	Select the correct option:
A) 5
B) 24
C) 7
D) 42
E) 6
36--- 6 DS = 6   ? ---- 1   48 ---- 6 US = 8   ? ---- 1 M = ?   M = (6 + 8)/2= 
<gadget id="calculator">(6 + 8)/2</gadget>
<output>7</output>
7   Answer: 7
<result>C</result>
A man swims downstream 36 km and upstream 48 km taking 6 hours each time, what is the speed of the man in still water?