diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..eaf3c7d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,62 @@
+# Compiled class files
+*.class
+
+# Log files
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# Virtual machine crash logs
+hs_err_pid*
+
+# Maven
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+.mvn/wrapper/maven-wrapper.jar
+
+# IntelliJ IDEA
+.idea/
+*.iws
+*.iml
+*.ipr
+out/
+
+# Eclipse
+.classpath
+.project
+.settings/
+bin/
+
+# NetBeans
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+# VS Code
+.vscode/
+
+# macOS
+.DS_Store
+
diff --git a/README.md b/README.md
index ce069b6..f71e30b 100644
--- a/README.md
+++ b/README.md
@@ -70,6 +70,34 @@ Once you finish the assignment, submit a URL link to your repository or your pul
 
 <br>
 
+## IntArrayList vs IntVector - Efficiency Analysis
+
+### When IntArrayList is More Efficient
+
+**IntArrayList** is more efficient when you have a **predictable growth pattern** with moderate additions to the list. Since it grows by 50% each time, it uses memory more conservatively and has less wasted space.
+
+**Example scenario:**
+- You're building a shopping cart system where users typically add 10-20 items
+- Starting with 10 slots and growing by 50% (10 → 15 → 22 → 33) is efficient
+- Less memory overhead compared to doubling
+- Fewer reallocations needed for moderate-sized collections
+
+### When IntVector is More Efficient
+
+**IntVector** is more efficient when you expect **rapid or unpredictable growth** in the number of elements. Doubling the capacity reduces the number of resize operations needed.
+
+**Example scenario:**
+- Processing a large data stream where you might receive hundreds or thousands of elements
+- Starting with 20 slots and doubling (20 → 40 → 80 → 160 → 320) reaches large capacities quickly
+- Fewer copy operations overall when dealing with large datasets
+- Better performance for bulk operations despite using more memory
+
+### Summary
+- **IntArrayList**: Better for small to medium collections with predictable growth (more memory efficient)
+- **IntVector**: Better for large or rapidly growing collections (fewer resize operations)
+
+<br>
+
 ## FAQs
 
 <br>
diff --git a/src/BigDecimalOperations.java b/src/BigDecimalOperations.java
new file mode 100644
index 0000000..1124bbf
--- /dev/null
+++ b/src/BigDecimalOperations.java
@@ -0,0 +1,15 @@
+
+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) {
+        return number.negate().setScale(1, RoundingMode.HALF_UP).doubleValue();
+    }
+}
+
diff --git a/src/Car.java b/src/Car.java
new file mode 100644
index 0000000..5cadd75
--- /dev/null
+++ b/src/Car.java
@@ -0,0 +1,51 @@
+
+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 void setVinNumber(String vinNumber) {
+        this.vinNumber = vinNumber;
+    }
+
+    public String getMake() {
+        return make;
+    }
+
+    public void setMake(String make) {
+        this.make = make;
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public void setModel(String model) {
+        this.model = model;
+    }
+
+    public int getMileage() {
+        return mileage;
+    }
+
+    public void setMileage(int mileage) {
+        this.mileage = mileage;
+    }
+
+    public String getInfo() {
+        return "VIN: " + vinNumber + ", Make: " + make + ", Model: " + model + ", Mileage: " + mileage + " miles";
+    }
+}
+
diff --git a/src/IntArrayList.java b/src/IntArrayList.java
new file mode 100644
index 0000000..ecc8e33
--- /dev/null
+++ b/src/IntArrayList.java
@@ -0,0 +1,39 @@
+
+public class IntArrayList implements IntList {
+    private int[] array;
+    private int size;
+
+    public IntArrayList() {
+        this.array = new int[10];
+        this.size = 0;
+    }
+
+    @Override
+    public void add(int number) {
+        if (size == array.length) {
+            int newLength = (int) (array.length * 1.5);
+            int[] newArray = new int[newLength];
+            System.arraycopy(array, 0, newArray, 0, array.length);
+            array = newArray;
+        }
+        array[size] = number;
+        size++;
+    }
+
+    @Override
+    public int get(int id) {
+        if (id < 0 || id >= size) {
+            throw new IndexOutOfBoundsException("Index " + id + " is out of bounds");
+        }
+        return array[id];
+    }
+
+    public int getSize() {
+        return size;
+    }
+
+    public int getCapacity() {
+        return array.length;
+    }
+}
+
diff --git a/src/IntList.java b/src/IntList.java
new file mode 100644
index 0000000..fda674a
--- /dev/null
+++ b/src/IntList.java
@@ -0,0 +1,6 @@
+
+public interface IntList {
+    void add(int number);
+    int get(int id);
+}
+
diff --git a/src/IntVector.java b/src/IntVector.java
new file mode 100644
index 0000000..74b8407
--- /dev/null
+++ b/src/IntVector.java
@@ -0,0 +1,39 @@
+
+public class IntVector implements IntList {
+    private int[] array;
+    private int size;
+
+    public IntVector() {
+        this.array = new int[20];
+        this.size = 0;
+    }
+
+    @Override
+    public void add(int number) {
+        if (size == array.length) {
+            int newLength = array.length * 2;
+            int[] newArray = new int[newLength];
+            System.arraycopy(array, 0, newArray, 0, array.length);
+            array = newArray;
+        }
+        array[size] = number;
+        size++;
+    }
+
+    @Override
+    public int get(int id) {
+        if (id < 0 || id >= size) {
+            throw new IndexOutOfBoundsException("Index " + id + " is out of bounds");
+        }
+        return array[id];
+    }
+
+    public int getSize() {
+        return size;
+    }
+
+    public int getCapacity() {
+        return array.length;
+    }
+}
+
diff --git a/src/Main.java b/src/Main.java
new file mode 100644
index 0000000..ffa00ca
--- /dev/null
+++ b/src/Main.java
@@ -0,0 +1,77 @@
+
+import java.math.BigDecimal;
+
+public class Main {
+    public static void main(String[] args) {
+        System.out.println("=== BigDecimal Operations ===");
+        testBigDecimalOperations();
+        
+        System.out.println("\n=== Car Inventory System ===");
+        testCarInventory();
+        
+        System.out.println("\n=== Video Streaming Service ===");
+        testVideoStreaming();
+        
+        System.out.println("\n=== IntList Interface ===");
+        testIntList();
+    }
+
+    private static void testBigDecimalOperations() {
+        BigDecimal num1 = new BigDecimal("4.2545");
+        System.out.println("Original: " + num1);
+        System.out.println("Rounded to nearest hundredth: " + 
+            BigDecimalOperations.roundToNearestHundredth(num1));
+        
+        BigDecimal num2 = new BigDecimal("1.2345");
+        System.out.println("\nOriginal: " + num2);
+        System.out.println("Reversed sign and rounded to nearest tenth: " + 
+            BigDecimalOperations.reverseSignAndRoundToNearestTenth(num2));
+        
+        BigDecimal num3 = new BigDecimal("-45.67");
+        System.out.println("\nOriginal: " + num3);
+        System.out.println("Reversed sign and rounded to nearest tenth: " + 
+            BigDecimalOperations.reverseSignAndRoundToNearestTenth(num3));
+    }
+
+    private static void testCarInventory() {
+        Sedan sedan = new Sedan("1HGBH41JXMN109186", "Honda", "Accord", 25000);
+        UtilityVehicle suv = new UtilityVehicle("5FNRL6H74HB123456", "Honda", "CR-V", 15000, true);
+        Truck truck = new Truck("1FTFW1ET5EFC10312", "Ford", "F-150", 30000, 13200.0);
+        
+        System.out.println(sedan.getInfo());
+        System.out.println(suv.getInfo());
+        System.out.println(truck.getInfo());
+    }
+
+    private static void testVideoStreaming() {
+        TvSeries series = new TvSeries("Breaking Bad", 3000, 62);
+        Movie movie = new Movie("The Shawshank Redemption", 142, 9.3);
+        
+        System.out.println(series.getInfo());
+        System.out.println(movie.getInfo());
+    }
+
+    private static void testIntList() {
+        System.out.println("Testing IntArrayList:");
+        IntArrayList arrayList = new IntArrayList();
+        for (int i = 0; i < 15; i++) {
+            arrayList.add(i * 10);
+            System.out.println("Added " + (i * 10) + " - Size: " + arrayList.getSize() + 
+                ", Capacity: " + arrayList.getCapacity());
+        }
+        
+        System.out.println("\nTesting IntVector:");
+        IntVector vector = new IntVector();
+        for (int i = 0; i < 25; i++) {
+            vector.add(i * 5);
+            System.out.println("Added " + (i * 5) + " - Size: " + vector.getSize() + 
+                ", Capacity: " + vector.getCapacity());
+        }
+        
+        System.out.println("\nRetrieving values from IntArrayList:");
+        for (int i = 0; i < 5; i++) {
+            System.out.println("Index " + i + ": " + arrayList.get(i));
+        }
+    }
+}
+
diff --git a/src/Movie.java b/src/Movie.java
new file mode 100644
index 0000000..7451d6e
--- /dev/null
+++ b/src/Movie.java
@@ -0,0 +1,23 @@
+
+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;
+    }
+
+    public void setRating(double rating) {
+        this.rating = rating;
+    }
+
+    @Override
+    public String getInfo() {
+        return "Movie - " + super.getInfo() + ", Rating: " + rating;
+    }
+}
+
diff --git a/src/Sedan.java b/src/Sedan.java
new file mode 100644
index 0000000..e0c5bb8
--- /dev/null
+++ b/src/Sedan.java
@@ -0,0 +1,13 @@
+
+public class Sedan extends Car {
+
+    public Sedan(String vinNumber, String make, String model, int mileage) {
+        super(vinNumber, make, model, mileage);
+    }
+
+    @Override
+    public String getInfo() {
+        return "Sedan - " + super.getInfo();
+    }
+}
+
diff --git a/src/Truck.java b/src/Truck.java
new file mode 100644
index 0000000..367c270
--- /dev/null
+++ b/src/Truck.java
@@ -0,0 +1,23 @@
+
+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;
+    }
+
+    public void setTowingCapacity(double towingCapacity) {
+        this.towingCapacity = towingCapacity;
+    }
+
+    @Override
+    public String getInfo() {
+        return "Truck - " + super.getInfo() + ", Towing Capacity: " + towingCapacity + " lbs";
+    }
+}
+
diff --git a/src/TvSeries.java b/src/TvSeries.java
new file mode 100644
index 0000000..968b7ac
--- /dev/null
+++ b/src/TvSeries.java
@@ -0,0 +1,23 @@
+
+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;
+    }
+
+    public void setEpisodes(int episodes) {
+        this.episodes = episodes;
+    }
+
+    @Override
+    public String getInfo() {
+        return "TV Series - " + super.getInfo() + ", Episodes: " + episodes;
+    }
+}
+
diff --git a/src/UtilityVehicle.java b/src/UtilityVehicle.java
new file mode 100644
index 0000000..76ab877
--- /dev/null
+++ b/src/UtilityVehicle.java
@@ -0,0 +1,23 @@
+
+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;
+    }
+
+    public void setFourWheelDrive(boolean fourWheelDrive) {
+        this.fourWheelDrive = fourWheelDrive;
+    }
+
+    @Override
+    public String getInfo() {
+        return "Utility Vehicle - " + super.getInfo() + ", Four Wheel Drive: " + fourWheelDrive;
+    }
+}
+
diff --git a/src/Video.java b/src/Video.java
new file mode 100644
index 0000000..733c68e
--- /dev/null
+++ b/src/Video.java
@@ -0,0 +1,31 @@
+
+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 void setTitle(String title) {
+        this.title = title;
+    }
+
+    public int getDuration() {
+        return duration;
+    }
+
+    public void setDuration(int duration) {
+        this.duration = duration;
+    }
+
+    public String getInfo() {
+        return "Title: " + title + ", Duration: " + duration + " minutes";
+    }
+}
+