diff --git a/src/main/java/_5/_2/Bill/Bill.java b/src/main/java/_5/_2/Bill/Bill.java
new file mode 100644
index 0000000..8ebd10c
--- /dev/null
+++ b/src/main/java/_5/_2/Bill/Bill.java
@@ -0,0 +1,64 @@
+package _5._2.Bill;
+
+import _5._2.CarComponents.*;
+
+public class Bill {
+    private Billtem[] items;
+
+    public Bill(Billtem[] items) {
+        this.items = items;
+    }
+
+    public double getTotalPrice() {
+        double price = 0;
+        for (Billtem i : items) {
+            price += i.getPrice();
+        }
+
+        return price;
+    }
+
+    public String toString() {
+        String string = "";
+        for (Billtem i : items) {
+            string += i.toString() + "\n";
+        }
+        double price = this.getTotalPrice();
+        string += "Total: " + price;
+        return string;
+    }
+
+
+    public static class Billtem {
+        private double price;
+        private CarComponent item;
+
+        public Billtem(CarComponent item, double price) {
+            this.item = item;
+            this.price = price;
+        }
+
+        public double getPrice() {
+            return price;
+        }
+
+        public String toString() {
+            return item.getName() + getComponents() + ": " + price;
+        }
+
+
+        public String getComponents() {
+            CarComponent[] components = item.getComponents();
+            String names = "";
+
+            if (components != null) {
+                names += "(";
+                for (CarComponent i : components) {
+                    names += i.getName() + " ";
+                }
+                names += ")";
+            }
+            return names;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/_5/_2/Bill/TestBill.java b/src/main/java/_5/_2/Bill/TestBill.java
new file mode 100644
index 0000000..c8f2809
--- /dev/null
+++ b/src/main/java/_5/_2/Bill/TestBill.java
@@ -0,0 +1,21 @@
+package _5._2.Bill;
+
+import _5._2.CarComponents.*;
+
+public class TestBill {
+    public static void main(String[] args) {
+        Motor m = new Motor("Motor",null);
+        Car c = new Car("Rolls Royce",new CarComponent[] {m});
+        Seat s = new Seat("Seat",null);
+        Wheel w1 = new Wheel("Wheel",null);
+        Wheel w2 = new Wheel("Wheel",null);
+        Wheel w3 = new Wheel("Wheel",null);
+        Wheel w4 = new Wheel("Wheel",null);
+
+        Bill.Billtem[] billtems = new Bill.Billtem[]{new Bill.Billtem(c, 100000.0), new Bill.Billtem(s,2000.0), new Bill.Billtem(w1, 1000.0), new Bill.Billtem(w2, 1000.0), new Bill.Billtem(w3, 1000.0), new Bill.Billtem(w4, 1000.0)};
+        Bill bill = new Bill(billtems);
+
+        String billprice = bill.toString();
+        System.out.println(billprice);
+    }
+}
diff --git a/src/main/java/_5/_2/CarComponents/Car.java b/src/main/java/_5/_2/CarComponents/Car.java
new file mode 100644
index 0000000..21c4ad7
--- /dev/null
+++ b/src/main/java/_5/_2/CarComponents/Car.java
@@ -0,0 +1,19 @@
+package _5._2.CarComponents;
+
+public class Car implements CarComponent {
+    private String name;
+    private CarComponent[] components;
+
+    public Car(String name, CarComponent[] components) {
+        this.name = name;
+        this.components = components;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public CarComponent[] getComponents() {
+        return components;
+    }
+}
diff --git a/src/main/java/_5/_2/CarComponents/CarComponent.java b/src/main/java/_5/_2/CarComponents/CarComponent.java
new file mode 100644
index 0000000..1108d8c
--- /dev/null
+++ b/src/main/java/_5/_2/CarComponents/CarComponent.java
@@ -0,0 +1,6 @@
+package _5._2.CarComponents;
+
+public interface CarComponent {
+    String getName();
+    CarComponent[] getComponents();
+}
\ No newline at end of file
diff --git a/src/main/java/_5/_2/CarComponents/CarPart.java b/src/main/java/_5/_2/CarComponents/CarPart.java
new file mode 100644
index 0000000..fa27dda
--- /dev/null
+++ b/src/main/java/_5/_2/CarComponents/CarPart.java
@@ -0,0 +1,19 @@
+package _5._2.CarComponents;
+
+public abstract class CarPart implements CarComponent {
+    private String name;
+    private CarComponent[] components;
+
+    public CarPart(String name,CarComponent[] components) {
+        this.name = name;
+        this.components = components;
+    }
+//
+    public String getName() {
+        return name;
+    }
+
+    public CarComponent[] getComponents() {
+        return components;
+    }
+}
diff --git a/src/main/java/_5/_2/CarComponents/Motor.java b/src/main/java/_5/_2/CarComponents/Motor.java
new file mode 100644
index 0000000..898b7ae
--- /dev/null
+++ b/src/main/java/_5/_2/CarComponents/Motor.java
@@ -0,0 +1,7 @@
+package _5._2.CarComponents;
+
+public final class Motor extends CarPart {
+    public Motor(String name,CarComponent[] components) {
+        super(name,components);
+    }
+}
diff --git a/src/main/java/_5/_2/CarComponents/Seat.java b/src/main/java/_5/_2/CarComponents/Seat.java
new file mode 100644
index 0000000..9a45808
--- /dev/null
+++ b/src/main/java/_5/_2/CarComponents/Seat.java
@@ -0,0 +1,7 @@
+package _5._2.CarComponents;
+
+public final class Seat extends CarPart {
+    public Seat(String name,CarComponent[] components) {
+        super(name,components);
+    }
+}
diff --git a/src/main/java/_5/_2/CarComponents/Wheel.java b/src/main/java/_5/_2/CarComponents/Wheel.java
new file mode 100644
index 0000000..464429c
--- /dev/null
+++ b/src/main/java/_5/_2/CarComponents/Wheel.java
@@ -0,0 +1,7 @@
+package _5._2.CarComponents;
+
+public final class Wheel extends CarPart {
+    public Wheel(String name,CarComponent[] components) {
+        super(name,components);
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/_5/_3/Group.java b/src/main/java/_5/_3/Group.java
new file mode 100644
index 0000000..b70dda2
--- /dev/null
+++ b/src/main/java/_5/_3/Group.java
@@ -0,0 +1,26 @@
+package _5._3;
+
+import java.util.LinkedList;
+
+public class Group<T extends Older> {
+    private LinkedList<T> members = new LinkedList<>();
+
+    public void add(T member) {
+        this.members.add(member);
+    }
+
+    public T getOldest() {
+        if (members.isEmpty()) {
+            return null;
+        }
+
+        T oldestMember = members.get(0);
+
+        for (int i=1; i<members.size(); i++) {
+            if (members.get(i).isOlder(oldestMember)) {
+                oldestMember = members.get(i);
+            }
+        }
+        return oldestMember;
+    }
+}
diff --git a/src/main/java/_5/_3/Older.java b/src/main/java/_5/_3/Older.java
new file mode 100644
index 0000000..8e038cc
--- /dev/null
+++ b/src/main/java/_5/_3/Older.java
@@ -0,0 +1,7 @@
+package _5._3;
+
+public interface Older<T> {
+    public boolean isOlder(T other);
+
+    public int getAge();
+}
diff --git a/src/main/java/_5/_3/Person.java b/src/main/java/_5/_3/Person.java
new file mode 100644
index 0000000..4856429
--- /dev/null
+++ b/src/main/java/_5/_3/Person.java
@@ -0,0 +1,23 @@
+package _5._3;
+
+public class Person<T extends Older> implements Older<T> {
+    private String name;
+    private int age;
+
+    public Person(String name, int age) {
+        this.name = name;
+        this.age = age;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public boolean isOlder(T other) {
+        return this.age > other.getAge();
+    }
+}