A girl swims downstream 112 km and upstream 32 km taking 8 hours each time, what is the speed of the girl in still water?	Pick one.
A) 8	B) 9	C) 10	D) 11	E) 12
112 --- 8 DS = 14   ? ---- 1   32 ---- 8 US = 4   ? ---- 1 M = ?   M = (14 + 4)/2= 
<gadget id="calculator">(14 + 4)/2</gadget>
<output>9</output>
9   Answer:9
<result>B</result>
A girl swims downstream 112 km and upstream 32 km taking 8 hours each time, what is the speed of the girl in still water?