Given:
11. abstract class Vehicle { public int speed() { return 0; }
12. class Car extends Vehicle { public int speed() { return 60; }
13. class RaceCar extends Car { public int speed() { return 150; } ...
21. RaceCar racer = new RaceCar();
22. Car car = new RaceCar();
23 Vehicle vehicle = new RaceCar();
24 System.out.println(racer.speed() + ", " + car.speed() + ", " + vehicle.speed ());
What is the result?