A boat can move upstream at 28 kmph and downstream at 50 kmph, then the speed of the current is?  Select the correct option.
A) 5 B) 6 C) 7 D) 54 E) 11
US = 28   DS = 50   M = (50 - 28)/2= 
<gadget id="calculator">(50 - 28)/2</gadget>
<output>11</output>
11.Answer:11
<result>E</result>
A boat can move upstream at 28 kmph and downstream at 50 kmph, then the speed of the current is?