A boat is traveling with a velocity of 18 meters/second
river is flowing at a velocity of 2.5 meters/second relative to the shore
if they are in opposite direction, the velocity of the boat would be:
v = 18 m/s - 2.5 m/sv = 15.5 m/s is the net velocity of the boat when a 2.5 m/s river is flowing opposite to it