diff --git a/src/main/java/com/dtcc/exams/arrays/IntegerArrayUtils.java b/src/main/java/com/dtcc/exams/arrays/IntegerArrayUtils.java
index 981c2dc..a69075d 100644
--- a/src/main/java/com/dtcc/exams/arrays/IntegerArrayUtils.java
+++ b/src/main/java/com/dtcc/exams/arrays/IntegerArrayUtils.java
@@ -1,13 +1,21 @@
 package com.dtcc.exams.arrays;
 
 public class IntegerArrayUtils {
+
+
     /**
      * @param integerArray - array to have value added to it
      * @param valueToBeAdded - value to be added to the end of the array
      * @return - identical array with one additional element of `valueToBeAdded` at the end of the array
      */
     public static Integer[] add(Integer[] integerArray, Integer valueToBeAdded) {
-        return null;
+        Integer[] newArray = new Integer[integerArray.length + 1];
+        for (int i = 0; i < integerArray.length; i++){
+            newArray[i] = integerArray[i];
+        }
+        newArray[newArray.length-1] = valueToBeAdded;
+
+        return newArray;
     }
 
     /**
@@ -17,7 +25,8 @@ public static Integer[] add(Integer[] integerArray, Integer valueToBeAdded) {
      * @return `integerArray` with `valueToBeInserted` at index number `indexToInsertAt`
      */
     public static Integer[] replace(Integer[] integerArray, int indexToInsertAt, Integer valueToBeInserted) {
-        return null;
+        integerArray[indexToInsertAt] = valueToBeInserted;
+        return integerArray;
     }
 
     /**
@@ -26,7 +35,8 @@ public static Integer[] replace(Integer[] integerArray, int indexToInsertAt, Int
      * @return element located at `indexToFetch`
      */
     public static Integer get(Integer[] integerArray, Integer indexToFetch) {
-        return null;
+        Integer value = integerArray[indexToFetch];
+        return value;
     }
 
     /**
@@ -34,7 +44,15 @@ public static Integer get(Integer[] integerArray, Integer indexToFetch) {
      * @return identical array with even-values incremented by 1 and odd-values decremented by 1
      */
     public static Integer[] incrementEvenDecrementOdd(Integer[] integerArray) {
-        return null;
+        for (int i = 0; i < integerArray.length; i++){
+            if (integerArray[i] % 2 == 0){
+                integerArray[i]+=1;
+            }
+            else{
+                integerArray[i]-=1;
+            }
+        }
+        return integerArray;
     }
 
     /**
@@ -42,7 +60,12 @@ public static Integer[] incrementEvenDecrementOdd(Integer[] integerArray) {
      * @return identical array with even-values incremented by 1
      */
     public static Integer[] incrementEven(Integer[] integerArray) {
-        return null;
+        for (int i = 0; i < integerArray.length; i++){
+            if (integerArray[i] % 2 == 0){
+                integerArray[i]+=1;
+            }
+        }
+        return integerArray;
     }
 
     /**
@@ -50,6 +73,11 @@ public static Integer[] incrementEven(Integer[] integerArray) {
      * @return identical array with odd-values decremented by 1
      */
     public static Integer[] decrementOdd(Integer[] input) {
-        return null;
+        for (int i = 0; i < input.length; i++){
+            if (input[i] % 2 != 0){
+                input[i]-=1;
+            }
+        }
+        return input;
     }
 }
diff --git a/src/main/java/com/dtcc/exams/arrays/StringArrayUtils.java b/src/main/java/com/dtcc/exams/arrays/StringArrayUtils.java
index 7ea3b16..f554815 100644
--- a/src/main/java/com/dtcc/exams/arrays/StringArrayUtils.java
+++ b/src/main/java/com/dtcc/exams/arrays/StringArrayUtils.java
@@ -8,7 +8,22 @@ public class StringArrayUtils {
      * @return an array with all elements between `startingIndex` and `endingIndex`
      */
     public static String[] getSubArray(String[] arrayToBeSpliced, int startingIndex, int endingIndex) {
-        return null;
+        int index = 0;
+        String[] splicedArray;
+        if(startingIndex >= 0 && endingIndex >= 0 && startingIndex < arrayToBeSpliced.length && endingIndex < arrayToBeSpliced.length){
+            splicedArray = new String[endingIndex-startingIndex];
+            for (int i = startingIndex; i < endingIndex; i++) {
+                splicedArray[index] = arrayToBeSpliced[i];
+                index++;
+            }
+        }
+        else if(startingIndex > arrayToBeSpliced.length && endingIndex > arrayToBeSpliced.length){
+            throw new IndexOutOfBoundsException();
+        }
+        else{
+            throw new IllegalArgumentException();
+        }
+        return splicedArray;
     }
 
 
@@ -18,6 +33,21 @@ public static String[] getSubArray(String[] arrayToBeSpliced, int startingIndex,
      * @return an array all elements between after `startingIndex`
      */
     public static String[] getEndingArray(String[] arrayToBeSpliced, int startingIndex) {
-        return null;
+        int index = 0;
+        String[] splicedArray;
+        if(startingIndex >= 0 && startingIndex < arrayToBeSpliced.length){
+            splicedArray = new String[arrayToBeSpliced.length-startingIndex];
+            for (int i = startingIndex; i < arrayToBeSpliced.length; i++) {
+                splicedArray[index] = arrayToBeSpliced[i];
+                index++;
+            }
+        }
+        else if(startingIndex > arrayToBeSpliced.length){
+            throw new IllegalArgumentException();
+        }
+        else{
+            throw new IndexOutOfBoundsException();
+        }
+        return splicedArray;
     }
 }
diff --git a/src/main/java/com/dtcc/exams/atm/Account.java b/src/main/java/com/dtcc/exams/atm/Account.java
index 85a4854..1ce1fda 100644
--- a/src/main/java/com/dtcc/exams/atm/Account.java
+++ b/src/main/java/com/dtcc/exams/atm/Account.java
@@ -1,25 +1,41 @@
 package com.dtcc.exams.atm;
 
 public class Account {
+
+    private double balance;
     
     public Account(double v) {
+        this.balance = v;
     }
 
     public double balance() {
-        return 0.0;
+        return this.balance;
     }
 
     public boolean closeAccount() {
-        return false;
+        boolean canClose = false;
+        if(balance == 0){
+            canClose = true;
+        }
+        return canClose;
     }
 
     public void deposit(double v) {
+        this.balance += v;
+
     }
 
     public Double withdraw(double v) {
-        return 0.0;
+        if(this.balance >= v){
+            this.balance = this.balance - v;
+        }
+        return this.balance;
     }
 
     public void transfer(Account b, double v) {
+        if(this.balance >= v){
+            b.balance = b.balance + v;
+            this.balance = this.balance - v;
+        }
     }
 }
diff --git a/src/main/java/com/dtcc/exams/collections/Inventory.java b/src/main/java/com/dtcc/exams/collections/Inventory.java
index 656eaaa..4f63ec3 100644
--- a/src/main/java/com/dtcc/exams/collections/Inventory.java
+++ b/src/main/java/com/dtcc/exams/collections/Inventory.java
@@ -1,16 +1,27 @@
 package com.dtcc.exams.collections;
 
+import java.util.HashMap;
 import java.util.List;
 
 /**
  * Use a map to keep track of inventory in a store
  */
 public class Inventory {
+    HashMap<String, Integer> inventory= new HashMap<>();
     /**
      * @param strings list of strings to add / remove / fetch from
      */
     public Inventory(List<String> strings) {
-
+        for(int i = 0; i< strings.size(); i++){
+            if(this.inventory.containsKey(strings.get(i))){
+                int j = this.inventory.get(strings.get(i)) + 1;
+                this.inventory.put(strings.get(i), j);
+            }
+            else{
+                this.inventory.put(strings.get(i), 1);
+            }
+        }
+        this.inventory = inventory;
     }
 
     /**
@@ -24,14 +35,22 @@ public Inventory() {
      * @param item - increment the number of this item in stock by 1
      */
     public void addItemToInventory(String item) {
-        return;
+        if(this.inventory.containsKey(item)){
+            int quantity = this.inventory.get(item);
+            this.inventory.put(item, quantity +1);
+        }
+        else {
+            this.inventory.put(item, 1);
+        }
     }
 
     /**
      * @param item - decrement the number of this item in stock by 1
      */
     public void removeItemFromInventory(String item) {
-        return;
+        if(this.inventory.containsKey(item)){
+            this.inventory.put(item, this.inventory.get(item) -1);
+        }
     }
 
     /**
@@ -39,6 +58,10 @@ public void removeItemFromInventory(String item) {
      * @return - return the number of items
      */
     public Integer getItemQuantity(String item) {
-        return null;
+        int quantity = 0;
+        if(this.inventory.containsKey(item)){
+            quantity = this.inventory.get(item);
+        }
+        return quantity;
     }
 }
diff --git a/src/main/java/com/dtcc/exams/collections/MonthConversion.java b/src/main/java/com/dtcc/exams/collections/MonthConversion.java
index f6a6dce..8d35cf5 100644
--- a/src/main/java/com/dtcc/exams/collections/MonthConversion.java
+++ b/src/main/java/com/dtcc/exams/collections/MonthConversion.java
@@ -1,31 +1,57 @@
 package com.dtcc.exams.collections;
 
+import java.util.HashMap;
+import java.util.Set;
+
 /**
  * Use a map to solve
  */
 public class MonthConversion {
+
+    HashMap<Integer, String> conversionMap = new HashMap<>();
     /**
-     * @param monthNumber - ordinal of month in the year; i.e. January = 1, February = 2
-     * @param monthName - name of month
+   //  * @param monthNumber - ordinal of month in the year; i.e. January = 1, February = 2
+   //  * @param monthName - name of month
      */
-    public void add(Integer monthNumber, String monthName) {
 
+    public MonthConversion(){
+        this.conversionMap = conversionMap;
+    }
+
+    public void add(Integer monthNumber, String monthName) {
+        this.conversionMap.put(monthNumber, monthName);
     }
 
+
+
     /**
      * @param monthNumber - ordinal of month in the year
      * @return the name of the respective month
      */
     public String getName(Integer monthNumber) {
-        throw new NullPointerException();
+        String monthName = null;
+        if(this.conversionMap.containsKey(monthNumber)){
+            monthName = this.conversionMap.get(monthNumber);
+        }
+//        else{
+//            throw new NullPointerException();
+//        }
+        return monthName;
     }
 
     /**
      * @param monthName - name of month
      * @return - the ordinal of the month in the year
      */
-    public int getNumber(String monthName) {
-        return (Integer)null;
+    public Integer getNumber(String monthName) {
+        Set<Integer> keys = this.conversionMap.keySet();
+        Integer numberResult = null;
+        for(Integer number : keys){
+            if(this.conversionMap.get(number).equals(monthName)){
+                numberResult = number;
+            }
+        }
+        return numberResult;
     }
 
     /**
@@ -33,7 +59,11 @@ public int getNumber(String monthName) {
      * @return true if the monthNumber is in the keySet
      */
     public Boolean isValidNumber(Integer monthNumber) {
-        return null;
+        boolean flag = false;
+        if(this.conversionMap.containsKey(monthNumber)){
+            flag = true;
+        }
+        return flag;
     }
 
     /**
@@ -41,14 +71,24 @@ public Boolean isValidNumber(Integer monthNumber) {
      * @return true if the monthName is in the valueSet
      */
     public Boolean isValidMonth(String monthName) {
-        return null;
+        boolean flag = false;
+        Set<Integer> keys = this.conversionMap.keySet();
+        for(Integer number : keys){
+            if(this.conversionMap.get(number).equals(monthName)){
+                flag = true;
+            }
+        }
+        return flag;
     }
 
     /**
      * @return number of entries in this mapping
      */
     public Integer size() {
-        return -1;
+        int size = 0;
+        Set keys = this.conversionMap.keySet();
+        size = keys.size();
+        return size;
     }
 
     /**
@@ -56,6 +96,6 @@ public Integer size() {
      * @param monthName - name of month
      */
     public void update(Integer monthNumber, String monthName) {
-
+        this.conversionMap.put(monthNumber, monthName);
     }
 }
diff --git a/src/main/java/com/dtcc/exams/fundamentals/BasicStringUtils.java b/src/main/java/com/dtcc/exams/fundamentals/BasicStringUtils.java
index eebed04..4f96176 100644
--- a/src/main/java/com/dtcc/exams/fundamentals/BasicStringUtils.java
+++ b/src/main/java/com/dtcc/exams/fundamentals/BasicStringUtils.java
@@ -7,7 +7,8 @@ public class BasicStringUtils {
      * @return concatenation of `string1` and `string2`
      */
     public static String concatentate(String string1, String string2) {
-        return null;
+        string1 += string2;
+        return string1;
     }
 
     /**
@@ -15,7 +16,11 @@ public static String concatentate(String string1, String string2) {
      * @return an identical string with characters in reverse order
      */
     public static String reverse(String string1) {
-        return null;
+        String string2 = "";
+        for(int i = string1.length()-1; i >= 0; i--){
+            string2 += string1.charAt(i);
+        }
+        return string2;
     }
 
     /**
@@ -24,7 +29,16 @@ public static String reverse(String string1) {
      * @return concatenation of the reverse of `string1` and reverse of `string2`
      */
     public static String reverseThenConcatenate(String string1, String string2) {
-        return null;
+        String string3 = "";
+        for(int i = string1.length()-1; i >= 0; i--){
+            string3 += string1.charAt(i);
+        }
+        String string4 = "";
+        for(int i = string2.length()-1; i >= 0; i--){
+            string4 += string2.charAt(i);
+        }
+        String string5 = string3 + string4;
+        return string5;
     }
 
     /**
@@ -33,7 +47,10 @@ public static String reverseThenConcatenate(String string1, String string2) {
      * @return `string` with `charactersToRemove` removed
      */
     public static String removeCharacters(String string, String charactersToRemove) {
-        return null;
+        for(int i = 0; i < charactersToRemove.length(); i++){
+            string = string.replaceAll(charactersToRemove.charAt(i)+"", "");
+        }
+        return string;
     }
 
     /**
@@ -42,6 +59,13 @@ public static String removeCharacters(String string, String charactersToRemove)
      * @return reverse of `string` with `charactersToRemove` removed
      */
     public static String removeCharactersThenReverse(String string, String charactersToRemove) {
-        return null;
+        for(int i = 0; i < charactersToRemove.length(); i++){
+            string = string.replaceAll(charactersToRemove.charAt(i)+"", "");
+        }
+        String string2 = "";
+        for(int i = string.length()-1; i >= 0; i--){
+            string2 += string.charAt(i);
+        }
+        return string2;
     }
 }
diff --git a/src/main/java/com/dtcc/exams/fundamentals/PredicateUtilities.java b/src/main/java/com/dtcc/exams/fundamentals/PredicateUtilities.java
index d5e94c5..3c994cb 100644
--- a/src/main/java/com/dtcc/exams/fundamentals/PredicateUtilities.java
+++ b/src/main/java/com/dtcc/exams/fundamentals/PredicateUtilities.java
@@ -6,7 +6,11 @@ public class PredicateUtilities {
      * @return true if `value` is a multiple of 2
      */
     public static Boolean isEven(Integer value) {
-        return null;
+        boolean flag = false;
+        if(value % 2 == 0){
+            flag = true;
+        }
+        return flag;
     }
 
     /**
@@ -14,7 +18,11 @@ public static Boolean isEven(Integer value) {
      * @return true if `value` is not a multiple of 2
      */
     public static Boolean isOdd(Integer value) {
-        return null;
+        boolean flag = true;
+        if(value % 2 == 0){
+            flag = false;
+        }
+        return flag;
     }
 
     /**
@@ -22,7 +30,11 @@ public static Boolean isOdd(Integer value) {
      * @return true if `value` is a multiple of 3
      */
     public static Boolean isMultipleOf3(Integer value) {
-        return null;
+        boolean flag = false;
+        if(value % 3 == 0){
+            flag = true;
+        }
+        return flag;
     }
 
     /**
@@ -32,7 +44,11 @@ public static Boolean isMultipleOf3(Integer value) {
      * @return true if `value` is a multiple of `multiple`
      */
     public static Boolean isMultipleOfN(Integer value, Integer multiple) {
-        return null;
+        boolean flag = false;
+        if(value % multiple == 0){
+            flag = true;
+        }
+        return flag;
     }
 
     /**
@@ -40,6 +56,10 @@ public static Boolean isMultipleOfN(Integer value, Integer multiple) {
      * @return true if `string` starts with a capital letter
      */
     public static Boolean startsWithCapitalLetter(String string) {
-        return null;
+        boolean flag = false;
+        if(string.charAt(0) >= 65 && string.charAt(0) <= 90){
+            flag = true;
+        }
+        return flag;
     }
 }
diff --git a/src/main/java/com/dtcc/exams/fundamentals/StringUtils.java b/src/main/java/com/dtcc/exams/fundamentals/StringUtils.java
index 5ef3237..4906c8b 100644
--- a/src/main/java/com/dtcc/exams/fundamentals/StringUtils.java
+++ b/src/main/java/com/dtcc/exams/fundamentals/StringUtils.java
@@ -8,7 +8,13 @@ public class StringUtils {
      * @return `stringToBePadded` flushed right by left-padding
      */
     public static String padLeft(String stringToBePadded, int amountOfPadding) {
-        return null;
+        String string = "";
+        for(int i = 0; i < amountOfPadding - stringToBePadded.length(); i++){
+            string += " ";
+        }
+        string += stringToBePadded;
+
+        return string;
     }
 
     /**
@@ -17,7 +23,11 @@ public static String padLeft(String stringToBePadded, int amountOfPadding) {
      * @return `stringToBePadded` flushed right by right-padding
      */
     public static String padRight(String stringToBePadded, int amountOfPadding) {
-        return null;
+        int length = stringToBePadded.length();
+        for(int i = 0; i < amountOfPadding - length; i++){
+            stringToBePadded += " ";
+        }
+        return stringToBePadded;
     }
 
     /**
@@ -26,7 +36,11 @@ public static String padRight(String stringToBePadded, int amountOfPadding) {
      * @return the string repeated and concatenated `n` times
      */
     public static String repeatString(String stringToBeRepeated, int numberOfTimeToRepeat) {
-        return null;
+        String string = "";
+        for(int i = 0; i < numberOfTimeToRepeat; i++){
+            string += stringToBeRepeated;
+        }
+        return string;
     }
 
     /**
@@ -34,7 +48,20 @@ public static String repeatString(String stringToBeRepeated, int numberOfTimeToR
      * @return - true if string only contains alpha characters
      */
     public static Boolean isAlphaString(String string) {
-        return null;
+        boolean flag = true;
+        int i = 0;
+        while(flag == true && i < string.length()){
+            if(string.charAt(i)<65 || (string.charAt(i)>90) && (string.charAt(i)<97) || string.charAt(i)>122){
+                if(string.charAt(i) == ' '){
+                    flag = true;
+                }
+                else{
+                    flag = false;
+                }
+            }
+            i++;
+        }
+        return flag;
     }
 
     /**
@@ -42,7 +69,15 @@ public static Boolean isAlphaString(String string) {
      * @return - true if string only contains numeric characters
      */
     public static Boolean isNumericString(String string) {
-        return null;
+        boolean flag = true;
+        int i = 0;
+        while(flag == true && i < string.length()){
+            if((string.charAt(i)< 48 || string.charAt(i)> 57)){
+                flag = false;
+            }
+            i++;
+        }
+        return flag;
     }
 
     /**
@@ -50,6 +85,16 @@ public static Boolean isNumericString(String string) {
      * @return - true if string only contains special characters
      */
     public static Boolean isSpecialCharacterString(String string) {
-        return null;
+        boolean flag = true;
+        int i = 0;
+        while(flag == true && i < string.length()){
+            if((string.charAt(i)>='0' && string.charAt(i)<='9') ||
+                    (string.charAt(i)>='A' && string.charAt(i)<='Z') ||
+                    ( string.charAt(i) >='a' && string.charAt(i) <='z')){
+                flag = false;
+            }
+            i++;
+        }
+        return flag;
     }
 }
diff --git a/src/main/java/com/dtcc/exams/oop/Address.java b/src/main/java/com/dtcc/exams/oop/Address.java
index ba86210..ddc4bab 100644
--- a/src/main/java/com/dtcc/exams/oop/Address.java
+++ b/src/main/java/com/dtcc/exams/oop/Address.java
@@ -1,7 +1,19 @@
 package com.dtcc.exams.oop;
 
 public class Address {
+
+    String addressLine1;
+    String addressLine2;
+    String city;
+    String state;
+    String zipcode;
+
     public Address() {
+        this.addressLine1 = "";
+        this.addressLine2 = "";
+        this.city = "";
+        this.state = "";
+        this.zipcode = "";
     }
 
     /**
@@ -12,45 +24,71 @@ public Address() {
      * @param zipcode - zipcode of region
      */
     public Address(String addressLine1, String addressLine2, String city, String state, String zipcode) {
+        this.addressLine1 = addressLine1;
+        this.addressLine2 = addressLine2;
+        this.city = city;
+        this.state = state;
+        this.zipcode = zipcode;
     }
 
     public String getAddressLine1() {
-        return null;
+        return this.addressLine1;
     }
 
     public void setAddressLine1(String addressLine1) {
+        this.addressLine1 = addressLine1;
     }
 
     public String getAddressLine2() {
-        return null;
+        return this.addressLine2;
     }
 
     public void setAddressLine2(String addressLine2) {
+        this.addressLine2 = addressLine2;
     }
 
     public String getCity() {
-        return null;
+        return this.city;
     }
 
     public void setCity(String city) {
+        this.city = city;
     }
 
     public String getState() {
-        return null;
+        return this.state;
     }
 
     public void setState(String state) {
+        this.state = state;
     }
 
     public String getZipcode() {
-        return null;
+        return this.zipcode;
     }
 
     public void setZipcode(String zipcode) {
+        this.zipcode = zipcode;
+    }
+
+    @Override
+    public String toString() {
+        String addressString = "Address{addressLine1='" + this.addressLine1 + "', addressLine2='" + this.addressLine2 + "', city='" + this.city + "', state='" + this.state + "', zipcode='" + this.zipcode + "'}";
+        return addressString;
     }
 
     @Override
     public boolean equals(Object o) {
-        return (Boolean)null;
+        Address address2 = (Address)o;
+        boolean flag = false;
+        if(this.state.equals(address2.getState()) &&
+                this.city.equals(address2.getCity()) &&
+                this.addressLine2.equals(address2.getAddressLine2()) &&
+                this.addressLine1.equals(address2.getAddressLine1()) &&
+                this.zipcode.equals(address2.getZipcode())){
+            flag = true;
+        }
+
+        return flag;
     }
 }
diff --git a/src/main/java/com/dtcc/exams/oop/Person.java b/src/main/java/com/dtcc/exams/oop/Person.java
index b8eff00..c55db1a 100644
--- a/src/main/java/com/dtcc/exams/oop/Person.java
+++ b/src/main/java/com/dtcc/exams/oop/Person.java
@@ -4,40 +4,61 @@
  * @ATTENTION_TO_STUDENTS - Ensure that you have completed the `Address` class before attempting this class
  */
 public class Person {
+    private Long id;
+    private String name;
+    private Address address;
+
     /**
      * @param id - id of person
      * @param name - name of person
      * @param address - address of person
      */
     public Person(Long id, String name, Address address) {
+        this.id = null;
+        this.name = "";
+        this.address = null;
+
     }
 
     public Person() {
+        this.id = id;
+        this.name = name;
+        this.address = address;
     }
 
     public Long getId() {
-        return null;
+        return this.id;
     }
 
     public void setId(Long id) {
+        this.id = id;
     }
 
     public String getName() {
-        return null;
+        return this.name;
     }
 
     public void setName(String name) {
+        this.name = name;
     }
 
     public Address getAddress() {
-        return null;
+        return this.address;
     }
 
     public void setAddress(Address address) {
+        this.address = address;
     }
 
     @Override
     public boolean equals(Object o) {
-        return (Boolean)null;
+        Person person2 = (Person)o;
+        boolean flag = false;
+        if(this.id == (person2.getId()) &&
+                this.name.equals(person2.getName()) &&
+                this.address.equals(person2.getAddress())){
+            flag = true;
+        }
+        return flag;
     }
 }
\ No newline at end of file
diff --git a/src/main/java/com/dtcc/exams/oop/animals/Animal.java b/src/main/java/com/dtcc/exams/oop/animals/Animal.java
index 2838689..4263cd4 100644
--- a/src/main/java/com/dtcc/exams/oop/animals/Animal.java
+++ b/src/main/java/com/dtcc/exams/oop/animals/Animal.java
@@ -2,12 +2,17 @@
 
 import com.dtcc.exams.oop.Address;
 import com.dtcc.exams.oop.Person;
-
 /**
  * @ATTENTION_TO_STUDENTS - Ensure that you have completed the `Person` class before attempting this class.
  */
 public class Animal {
+
+    private Long id;
+    private Person owner;
+
     public Animal() {
+        this.id = null;
+        this.owner = owner;
     }
 
     /**
@@ -15,23 +20,27 @@ public Animal() {
      * @param owner - owner of animal
      */
     public Animal(Long id, Person owner) {
+        this.id = id;
+        this.owner = owner;
     }
 
     public Long getId() {
-        return null;
+        return this.id;
     }
 
     public void setId(Long id) {
+        this.id = id;
     }
 
     public Person getOwner() {
-        return null;
+        return this.owner;
     }
 
     public void setOwner(Person owner) {
+        this.owner = owner;
     }
 
     public Address getAddress() {
-        return null;
+        return this.owner.getAddress();
     }
 }
diff --git a/src/main/java/com/dtcc/exams/oop/animals/Dog.java b/src/main/java/com/dtcc/exams/oop/animals/Dog.java
index 5401e48..0b917cd 100644
--- a/src/main/java/com/dtcc/exams/oop/animals/Dog.java
+++ b/src/main/java/com/dtcc/exams/oop/animals/Dog.java
@@ -3,8 +3,8 @@
 /**
  * @ATTENTION_TO_STUDENTS - Ensure that you completed the `Animal` class before attempting this class
  */
-public class Dog {
+public class Dog extends Animal{
     public String speak() {
-        return null;
+        return "Woof";
     }
 }
diff --git a/src/main/java/com/dtcc/exams/oop/animals/Woofer.java b/src/main/java/com/dtcc/exams/oop/animals/Woofer.java
index 6d53313..4fc8006 100644
--- a/src/main/java/com/dtcc/exams/oop/animals/Woofer.java
+++ b/src/main/java/com/dtcc/exams/oop/animals/Woofer.java
@@ -1,5 +1,5 @@
 package com.dtcc.exams.oop.animals;
 
-public class Woofer {
+public class Woofer extends Dog{
 
 }