A boat can move upstream at 25 kmph and downstream at 30 kmph, then the speed of the current is? Pick one:
A) 5  B) 6  C) 7  D) 2.5  E) 9
US = 25   2.5S = 30   M = (35 - 25)/2 = 2.5   Answer: 2.5
<result>D</result>
A boat can move upstream at 25 kmph and downstream at 30 kmph, then the speed of the current is?