diff --git a/src/main/java/LoopFun.java b/src/main/java/LoopFun.java
index 801ab56..c054f28 100644
--- a/src/main/java/LoopFun.java
+++ b/src/main/java/LoopFun.java
@@ -1,4 +1,3 @@
- 
 
 public class LoopFun
 {
@@ -10,7 +9,11 @@ public class LoopFun
        * @return the factorial of the number
        */
       public Integer factorial(Integer number){
-          return null;
+          int factorial = 1;
+          for (int i = 1; i <= number; i++) {
+              factorial *= i;
+          }
+          return factorial;
       }
 
       /**
@@ -21,7 +24,9 @@ public Integer factorial(Integer number){
        * @return Upper case string of the first letter of each word
        */
       public String acronym(String phrase) {
-          return null;
+          String s = phrase;
+          String result = s.replaceAll("\\B.|\\P{L}", "").toUpperCase();
+          return result;
       }
 
       /**
@@ -37,6 +42,14 @@ public String acronym(String phrase) {
        * @return the encrypted string by shifting each character by three character
        */
       public String encrypt(String word) {
-          return null;
+          String encrypt = "";
+          for (int i = 0; i < word.length(); i++) {
+              char letter = word.charAt(i);
+              letter += 3;
+              if (letter > 'z') letter -= 26;
+              encrypt += letter;
+          }
+          return encrypt;
       }
-}
+
+}
\ No newline at end of file
diff --git a/src/main/java/MathUtilities.java b/src/main/java/MathUtilities.java
index e067c75..61c5985 100644
--- a/src/main/java/MathUtilities.java
+++ b/src/main/java/MathUtilities.java
@@ -9,7 +9,8 @@ public class MathUtilities{
    * @return the sum of the two numbers
    */
   public Integer add(Integer baseValue, Integer valueToAdd){
-      return null;
+      int sum = baseValue + valueToAdd;
+      return sum;
   }
 
   /**
@@ -19,7 +20,8 @@ public Integer add(Integer baseValue, Integer valueToAdd){
    * @return the sum of the two numbers
    */
   public Double add(Double baseValue, Double valueToAdd){
-      return null;
+      double sum = baseValue + valueToAdd;
+      return sum;
   }
 
   /**
@@ -28,7 +30,8 @@ public Double add(Double baseValue, Double valueToAdd){
    * @return the half of the number in double
    */
   public Double half(Integer number) {
-      return null;
+      double half = number * 0.5;
+      return half;
   }
 
   /**
@@ -37,7 +40,11 @@ public Double half(Integer number) {
    * @return true if the number is odd, false if it is even
    */
   public Boolean isOdd(Integer number){
-      return null;
+      if (number % 2 != 0) {
+          return true;
+      } else {
+          return false;
+      }
   }
 
 
@@ -47,7 +54,8 @@ public Boolean isOdd(Integer number){
    * @return the result of the number multiply by itself
    */
   public Integer square(Integer number) {
-      return null;
+      int square = number * number;
+      return square;
   }
 
 }
diff --git a/src/main/java/StringUtilities.java b/src/main/java/StringUtilities.java
index e3ea8a9..0c683a1 100644
--- a/src/main/java/StringUtilities.java
+++ b/src/main/java/StringUtilities.java
@@ -5,7 +5,7 @@ public class StringUtilities {
      * @return `input`
      */
     public String returnInput(String input) {
-        return null;
+        return input;
     }
 
     /**
@@ -14,7 +14,8 @@ public String returnInput(String input) {
      * @return the concatenation of `baseValue` and `valueToBeAdded`
      */
     public String concatenate(String baseValue, String valueToBeAdded) {
-        return null;
+        String concatenate = baseValue + valueToBeAdded;
+        return concatenate;
     }
 
     /**
@@ -22,7 +23,11 @@ public String concatenate(String baseValue, String valueToBeAdded) {
      * @return identical string with characters in opposite order
      */
     public String reverse(String valueToBeReversed) {
-        return null;
+        // Declaring a StringBuilder and converting string to StringBuilder
+        StringBuilder reverseString = new StringBuilder(valueToBeReversed);
+        reverseString.reverse(); // Reversing the StringBuilder
+        String result = reverseString.toString(); // Converting StringBuilder to String
+        return result; // Returns the reversed String
     }
 
     /**
@@ -30,7 +35,9 @@ public String reverse(String valueToBeReversed) {
      * @return middle character of `word`
      */
     public Character getMiddleCharacter(String word) {
-        return null;
+        int length = word.length();
+        int middleOfWord = length / 2;
+        return word.charAt(middleOfWord);
     }
 
     /**
@@ -39,7 +46,8 @@ public Character getMiddleCharacter(String word) {
      * @return `value` with char of value `charToRemove` removed
      */
     public String removeCharacter(String value, Character charToRemove) {
-        return null;
+        String strNew = value.replace(String.valueOf(charToRemove), "");
+        return strNew;
     }
 
     /**
@@ -47,6 +55,7 @@ public String removeCharacter(String value, Character charToRemove) {
      * @return last `word` in sentence
      */
     public String getLastWord(String sentence) {
-        return null;
+        String lastWord = sentence.substring(sentence.lastIndexOf(" ")+1);
+        return lastWord;
     }
 }