diff --git a/BigDecimalOperations.java b/BigDecimalOperations.java
new file mode 100644
index 0000000..809476c
--- /dev/null
+++ b/BigDecimalOperations.java
@@ -0,0 +1,14 @@
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+
+public class BigDecimalOperations {
+
+    public static double roundToNearestHundredth(BigDecimal number) {
+        return number.setScale(2, RoundingMode.HALF_UP).doubleValue();
+    }
+
+    public static double reverseSignAndRoundToNearestTenth(BigDecimal number) {
+        BigDecimal reversed = number.negate();
+        return reversed.setScale(1, RoundingMode.HALF_UP).doubleValue();
+    }
+}
\ No newline at end of file
diff --git a/Car.java b/Car.java
new file mode 100644
index 0000000..116a9e4
--- /dev/null
+++ b/Car.java
@@ -0,0 +1,36 @@
+public abstract class Car {
+    private String vinNumber;
+    private String make;
+    private String model;
+    private int mileage;
+
+    public Car(String vinNumber, String make, String model, int mileage) {
+        this.vinNumber = vinNumber;
+        this.make = make;
+        this.model = model;
+        this.mileage = mileage;
+    }
+
+    public String getVinNumber() {
+        return vinNumber;
+    }
+
+    public String getMake() {
+        return make;
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public int getMileage() {
+        return mileage;
+    }
+
+    public String getInfo() {
+        return "VIN: " + vinNumber +
+                ", Make: " + make +
+                ", Model: " + model +
+                ", Mileage: " + mileage;
+    }
+}
\ No newline at end of file
diff --git a/IntArrayList.java b/IntArrayList.java
new file mode 100644
index 0000000..36f82b0
--- /dev/null
+++ b/IntArrayList.java
@@ -0,0 +1,42 @@
+public class IntArrayList implements IntList {
+
+    private int[] numbers;
+    private int size;
+
+    public IntArrayList() {
+        numbers = new int[10]; // tamaño inicial 10
+        size = 0;
+    }
+
+    @Override
+    public void add(int number) {
+
+        // Si el array está lleno, lo ampliamos un 50%
+        if (size == numbers.length) {
+
+            int newLength = numbers.length + (numbers.length / 2);
+            int[] newArray = new int[newLength];
+
+            // Copiar elementos al nuevo array
+            for (int i = 0; i < numbers.length; i++) {
+                newArray[i] = numbers[i];
+            }
+
+            numbers = newArray;
+        }
+
+        // Añadir el nuevo número
+        numbers[size] = number;
+        size++;
+    }
+
+    @Override
+    public int get(int id) {
+
+        if (id < 0 || id >= size) {
+            throw new IndexOutOfBoundsException("Índice fuera de rango");
+        }
+
+        return numbers[id];
+    }
+}
diff --git a/IntList.java b/IntList.java
new file mode 100644
index 0000000..5f800aa
--- /dev/null
+++ b/IntList.java
@@ -0,0 +1,4 @@
+public interface IntList {
+    void add(int number);
+    int get(int id);
+}
\ No newline at end of file
diff --git a/IntVector.java b/IntVector.java
new file mode 100644
index 0000000..e227ac4
--- /dev/null
+++ b/IntVector.java
@@ -0,0 +1,34 @@
+public class IntVector implements IntList {
+    private int[] numbers;
+    private int size;
+
+    public IntVector() {
+        numbers = new int[20];
+        size = 0;
+    }
+
+    @Override
+    public void add(int number) {
+        if (size == numbers.length) {
+            int newLength = numbers.length * 2;
+            int[] newArray = new int[newLength];
+
+            for (int i = 0; i < numbers.length; i++) {
+                newArray[i] = numbers[i];
+            }
+
+            numbers = newArray;
+        }
+
+        numbers[size] = number;
+        size++;
+    }
+
+    @Override
+    public int get(int id) {
+        if (id < 0 || id >= size) {
+            throw new IndexOutOfBoundsException("Índice fuera de rango");
+        }
+        return numbers[id];
+    }
+}
diff --git a/Main.java b/Main.java
new file mode 100644
index 0000000..22829fa
--- /dev/null
+++ b/Main.java
@@ -0,0 +1,57 @@
+import java.math.BigDecimal;
+
+public class Main {
+    public static void main(String[] args) {
+
+        System.out.println("=== BIGDECIMAL OPERATIONS ===");
+        BigDecimal num1 = new BigDecimal("4.2545");
+        BigDecimal num2 = new BigDecimal("1.2345");
+        BigDecimal num3 = new BigDecimal("-45.67");
+
+        System.out.println("Rounded to nearest hundredth: " +
+                BigDecimalOperations.roundToNearestHundredth(num1));
+
+        System.out.println("Reverse sign and round to nearest tenth (1.2345): " +
+                BigDecimalOperations.reverseSignAndRoundToNearestTenth(num2));
+
+        System.out.println("Reverse sign and round to nearest tenth (-45.67): " +
+                BigDecimalOperations.reverseSignAndRoundToNearestTenth(num3));
+
+        System.out.println();
+        System.out.println("=== CAR INVENTORY SYSTEM ===");
+
+        Car sedan = new Sedan("VIN001", "Toyota", "Corolla", 50000);
+        Car suv = new UtilityVehicle("VIN002", "Jeep", "Cherokee", 30000, true);
+        Car truck = new Truck("VIN003", "Ford", "F-150", 45000, 3500.5);
+
+        System.out.println(sedan.getInfo());
+        System.out.println(suv.getInfo());
+        System.out.println(truck.getInfo());
+
+        System.out.println();
+        System.out.println("=== VIDEO STREAMING SERVICE ===");
+
+        Video series = new TvSeries("Breaking Bad", 50, 62);
+        Video movie = new Movie("Inception", 148, 8.8);
+
+        System.out.println(series.getInfo());
+        System.out.println(movie.getInfo());
+
+        System.out.println();
+        System.out.println("=== INTLIST INTERFACE ===");
+
+        IntList arrayList = new IntArrayList();
+        IntList vector = new IntVector();
+
+        arrayList.add(10);
+        arrayList.add(20);
+        arrayList.add(30);
+
+        vector.add(100);
+        vector.add(200);
+        vector.add(300);
+
+        System.out.println("IntArrayList element at index 1: " + arrayList.get(1));
+        System.out.println("IntVector element at index 2: " + vector.get(2));
+    }
+}
\ No newline at end of file
diff --git a/Movie.java b/Movie.java
new file mode 100644
index 0000000..5024857
--- /dev/null
+++ b/Movie.java
@@ -0,0 +1,17 @@
+public class Movie extends Video {
+    private double rating;
+
+    public Movie(String title, int duration, double rating) {
+        super(title, duration);
+        this.rating = rating;
+    }
+
+    public double getRating() {
+        return rating;
+    }
+
+    @Override
+    public String getInfo() {
+        return super.getInfo() + ", Rating: " + rating;
+    }
+}
\ No newline at end of file
diff --git a/Sedan.java b/Sedan.java
new file mode 100644
index 0000000..3a23fd3
--- /dev/null
+++ b/Sedan.java
@@ -0,0 +1,6 @@
+public class Sedan extends Car {
+
+    public Sedan(String vinNumber, String make, String model, int mileage) {
+        super(vinNumber, make, model, mileage);
+    }
+}
\ No newline at end of file
diff --git a/Truck.java b/Truck.java
new file mode 100644
index 0000000..5391600
--- /dev/null
+++ b/Truck.java
@@ -0,0 +1,17 @@
+public class Truck extends Car {
+    private double towingCapacity;
+
+    public Truck(String vinNumber, String make, String model, int mileage, double towingCapacity) {
+        super(vinNumber, make, model, mileage);
+        this.towingCapacity = towingCapacity;
+    }
+
+    public double getTowingCapacity() {
+        return towingCapacity;
+    }
+
+    @Override
+    public String getInfo() {
+        return super.getInfo() + ", Towing Capacity: " + towingCapacity;
+    }
+}
\ No newline at end of file
diff --git a/TvSeries.java b/TvSeries.java
new file mode 100644
index 0000000..3a256cf
--- /dev/null
+++ b/TvSeries.java
@@ -0,0 +1,17 @@
+public class TvSeries extends Video {
+    private int episodes;
+
+    public TvSeries(String title, int duration, int episodes) {
+        super(title, duration);
+        this.episodes = episodes;
+    }
+
+    public int getEpisodes() {
+        return episodes;
+    }
+
+    @Override
+    public String getInfo() {
+        return super.getInfo() + ", Episodes: " + episodes;
+    }
+}
\ No newline at end of file
diff --git a/UtilityVehicle.java b/UtilityVehicle.java
new file mode 100644
index 0000000..14c65ea
--- /dev/null
+++ b/UtilityVehicle.java
@@ -0,0 +1,17 @@
+public class UtilityVehicle extends Car {
+    private boolean fourWheelDrive;
+
+    public UtilityVehicle(String vinNumber, String make, String model, int mileage, boolean fourWheelDrive) {
+        super(vinNumber, make, model, mileage);
+        this.fourWheelDrive = fourWheelDrive;
+    }
+
+    public boolean isFourWheelDrive() {
+        return fourWheelDrive;
+    }
+
+    @Override
+    public String getInfo() {
+        return super.getInfo() + ", Four Wheel Drive: " + fourWheelDrive;
+    }
+}
\ No newline at end of file
diff --git a/Video.java b/Video.java
new file mode 100644
index 0000000..f2b1fdf
--- /dev/null
+++ b/Video.java
@@ -0,0 +1,21 @@
+public abstract class Video {
+    private String title;
+    private int duration;
+
+    public Video(String title, int duration) {
+        this.title = title;
+        this.duration = duration;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public int getDuration() {
+        return duration;
+    }
+
+    public String getInfo() {
+        return "Title: " + title + ", Duration: " + duration + " minutes";
+    }
+}
\ No newline at end of file