A man swims downstream 60 km and upstream 40 km taking 4 hours each time; what is the speed of the current?	Pick:	A) 3 kmph	B) 2.5 kmph	C) 13 kmph	D) 6.5 kmph	E) 7:3kmph
Explanation:   60 --- 4 DS = 15   ? ---- 1   40 ---- 4 US = 10   ? ---- 1 S = ?   S = (15 - 10)/2= 
<gadget id="calculator">(15 - 10)/2</gadget>
<output>5/2 = around 2.5</output>
2.5   Answer: Option 2.5 kmph
<result>B</result>
A man swims downstream 60 km and upstream 40 km taking 4 hours each time; what is the speed of the current?