diff --git a/src/main/java/Unit4/U4_L4_Activity_One.java b/src/main/java/Unit4/U4_L4_Activity_One.java
new file mode 100644
index 0000000..b19a3d1
--- /dev/null
+++ b/src/main/java/Unit4/U4_L4_Activity_One.java
@@ -0,0 +1,32 @@
+package Unit4;
+
+import java.util.Scanner;
+
+public class U4_L4_Activity_One {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        String string = scanner.nextLine().toLowerCase();
+        int pTimes = 0;
+
+        for (int i = 0; i < string.length(); i++) {
+            if (string.substring(i, i + 1).equals("p")) {
+                String nextLetter = string.substring(i + 1, i + 2);
+                boolean isVowel = nextLetter.equals("a") ||
+                        nextLetter.equals("e") ||
+                        nextLetter.equals("i") ||
+                        nextLetter.equals("i") ||
+                        nextLetter.equals("o") ||
+                        nextLetter.equals("u");
+
+                if (isVowel) {
+                    pTimes++;
+                }
+            }
+        }
+
+        System.out.println("Contains p followed by a vowel " + pTimes + " times.");
+        scanner.close();
+    }
+
+}
diff --git a/src/main/java/Unit4/U4_L4_Activity_Three.java b/src/main/java/Unit4/U4_L4_Activity_Three.java
new file mode 100644
index 0000000..39c2a4b
--- /dev/null
+++ b/src/main/java/Unit4/U4_L4_Activity_Three.java
@@ -0,0 +1,25 @@
+package Unit4;
+
+import java.util.Scanner;
+
+public class U4_L4_Activity_Three {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        String word1 = scanner.nextLine();
+        String word2 = scanner.nextLine();
+
+        if (word1.length() == word2.length()) {
+            
+            for (int i = word1.length(); i > 0; i--) {
+                System.out.print(word2.substring(i - 1, i));
+                System.out.print(word1.substring(i - 1, i));
+            }
+
+        } else {
+            System.out.println("error");
+        }
+
+        scanner.close();
+    }
+}
diff --git a/src/main/java/Unit4/U4_L4_Activity_Two.java b/src/main/java/Unit4/U4_L4_Activity_Two.java
new file mode 100644
index 0000000..f809d66
--- /dev/null
+++ b/src/main/java/Unit4/U4_L4_Activity_Two.java
@@ -0,0 +1,29 @@
+package Unit4;
+
+import java.util.Scanner;
+
+public class U4_L4_Activity_Two {
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        String string = scanner.nextLine().toLowerCase();
+
+        String newString = "";
+
+        for (int i = 0; i < string.length(); i++) {
+            String letter = string.substring(i, i + 1);
+            boolean isMostCommonLetter = letter.equals("e") ||
+                    letter.equals("t") ||
+                    letter.equals("a") ||
+                    letter.equals("i") ||
+                    letter.equals("o");
+            if(!isMostCommonLetter){
+                newString+=letter;
+            }
+        }
+
+        System.out.println(newString);
+        scanner.close();
+    }
+}