A boat can move upstream at 22 kmph and downstream at 42 kmph, then the speed of the current is?
Choose the correct choice from the following choices:  A) 5  B) 6  C) 7  D) 10  E) 3
US = 22   10S = 42   M = (42 - 22)/2= 
<gadget id="calculator">(42 - 22)/2</gadget>
<output>10</output>
10.Answer:10
<result>D</result>
A boat can move upstream at 22 kmph and downstream at 42 kmph, then the speed of the current is?