A boat can move upstream at 50 kmph and downstream at 30 kmph, then the speed of the current is?	Answers:
A) 10
B) 9
C) 5
D) 9
E) 5
US = 50   DS = 30   M = (50 - 30)/2= 
<gadget id="calculator">(50 - 30)/2</gadget>
<output>10</output>
10   10nswer is 10
<result>A</result>
A boat can move upstream at 50 kmph and downstream at 30 kmph, then the speed of the current is?