A man swims downstream 72 km and upstream 45 km taking 6 hours each time; what is the speed of the current?	Choose the correct choice:
A) 2.28 B) 2.24 C) 2.27 D) 2.25 E) 2.23
72 --- 6 2.25S = 12   ? ---- 1   45 ---- 6 US = 7.5   ? ---- 1 S = ?   S = (12 - 7.5)/2= 
<gadget id="calculator">(12 - 7.5)/2</gadget>
<output>2.25</output>
2.25   Answer:2.25
<result>D</result>
A man swims downstream 72 km and upstream 45 km taking 6 hours each time; what is the speed of the current?