A man swims downstream 72 km and upstream 45 km taking 9 hours each time; what is the speed of the current?  Options.
A) 1.9  B) 1.5  C) 1.4  D) 1.1  E) 1.2
72 --- 9 DS = 8   ? ---- 1   45 ---- 9 US = 5   ? ---- 1 S = ?   S = (8 - 5)/2= 
<gadget id="calculator">(8 - 5)/2</gadget>
<output>3/2 = around 1.5</output>
1.5   Answer: 1.5
<result>B</result>
A man swims downstream 72 km and upstream 45 km taking 9 hours each time; what is the speed of the current?