A man swims downstream 72 km and upstream 45 km taking 10 hours each time; what is the speed of the current?  Answers.
A) 1.55
B) 1.85
C) 1.65
D) 1.35
E) 1.15
72 --- 10 1.35S = 7.2   ? ---- 1   45 ---- 10 US = 4.5   ? ---- 1 S = ?   S = (7.2 - 4.5)/2= 
<gadget id="calculator">(7.2 - 4.5)/2</gadget>
<output>1.35</output>
1.35   Answer:1.35
<result>D</result>
A man swims downstream 72 km and upstream 45 km taking 10 hours each time; what is the speed of the current?