IN a typical Indian Bugghi(a luxury cart drawn by horses), a wooden plate is fixed on the rear on which one person can sit. A bughi ofmas 200 kg is moving at a seed of 10 km/h. As it overtakes a school boy walking at a speed of 4 km/h,. the boy sits on the wooden plate. If the mass of the boy is 25 kg, what will be the new velocity of the bugghi?