Question

A person riding in the back of a pickup truck traveling at 60km/h on a straight, level road throws a ball with a speed of 10km/h relative to the truck in the direction of the truck's motion.What is the velocity of the ball relative to a stationary observer by the side of the road?What is the velocity of the ball relative to the driver of a car moving in the same direction as the truck at a speed of 80km/h ?