package javafuture; import javafx.scene.Parent; import java.util.*; public class Example { public static void main(String[] args) { Buyer b = new Buyer(); TV tv=new TV(); Computer com=new Computer(); Audio audio =new Audio(); b.buy(tv); b.buy(com); b.buy(audio); System.out.println(b.bonusPoint); System.out.println(b.money); b.summary(); System.out.println(); b.refund(com); b.summary(); } } class..

package javafuture; import javafx.scene.Parent; public class Example { public static void main(String[] args) { Buyer b = new Buyer(); b.buy(new TV()); b.buy(new Computer()); b.buy(new Audio()); System.out.println(b.bonusPoint); System.out.println(b.money); b.summary(); } } class Product { int price; int bonusPoint; Product(int price) { this.price = price; bonusPoint = (int) (price / 10); } Prod..

package javafuture; import javafx.scene.Parent; public class Example { public static void main(String[] args) { Buyer b=new Buyer(); b.buy(new Tv()); b.buy(new Computer()); System.out.println(b.money); System.out.println(b.bonusPoint); } } class Product{ int price; // product's price int bonusPoint; // membership point when you buy something Product(int price){ this.price=price; this.bonusPoint=..