diff --git a/src/main/java/com/booleanuk/core/Exercise.java b/src/main/java/com/booleanuk/core/Exercise.java
index 5b1fe79..7a0d700 100644
--- a/src/main/java/com/booleanuk/core/Exercise.java
+++ b/src/main/java/com/booleanuk/core/Exercise.java
@@ -7,7 +7,7 @@ public class Exercise {
     // 1. The brokenUrl member above contains an invalid URL. There's a z instead of an s in the protocol (httpz instead of https).
     // Using the `replace` method on brokenUrl, set the fixedUrl member below to the correct value.
     // https://docs.oracle.com/en/java/javase/18/docs/api/java.base/java/lang/String.html#replace(char,char)
-    public String fixedUrl = "";
+    public String fixedUrl = brokenUrl.replace('z', 's');
 
 
     // Here's a documentation link for all string methods, use it to figure out how to complete the rest of these requirements:
@@ -16,26 +16,26 @@ public class Exercise {
 
     // 2. There are currently some upper case characters in the URL. Using an appropriate string method on the fixedUrl member above,
     // set the value of lowerCasedUrl.
-    public String lowerCasedUrl = "";
+    public String lowerCasedUrl = fixedUrl.toLowerCase();
 
 
     // 3. There is still white space on both ends of the URL! Use the appropriate string method to trim that white space
     // and set the value of the url member below
-    public String url = "";
+    public String url = lowerCasedUrl.strip();
 
 
     // 4. Using the appropriate string method on url, set the value of the protocol member below
-    public String protocol = "";
+    public String protocol = url.split(":")[0];
 
 
     // 5. Using the appropriate string method on url, set the value of the domain member below
-    public String domain = "";
+    public String domain = url.split("/")[2];
 
 
     // 6. Set the length member below to the length of the url member
-    public int length = 0;
+    public int length = url.length();
 
 
     // 7. Using concatenation and existing members, set the faqUrl member below to the faq page of the boolean website
-    public String faqUrl = "";
+    public String faqUrl = protocol + "://" + domain + "/faq";
 }
diff --git a/src/main/java/com/booleanuk/extension/Extension.java b/src/main/java/com/booleanuk/extension/Extension.java
index 5f84cdb..f48cf62 100644
--- a/src/main/java/com/booleanuk/extension/Extension.java
+++ b/src/main/java/com/booleanuk/extension/Extension.java
@@ -29,7 +29,7 @@ public StringBuilder one() {
         // 1. Using the sb variable above, add "Hello, world!" to the StringBuilder
         // WRITE YOUR CODE BETWEEN THIS LINE...
 
-
+        sb.append("Hello, world!");
 
         // ...AND THIS LINE
 
@@ -43,7 +43,8 @@ public StringBuilder two() {
         // 2. After adding the message, use an appropriate StringBuilder method to reverse it
         // WRITE YOUR CODE BETWEEN THIS LINE...
 
-
+        sb.append("Hello, world!");
+        sb.reverse();
 
         // ...AND THIS LINE
 
@@ -57,7 +58,8 @@ public StringBuilder three() {
         // 2. After adding the message, remove the comma.
         // WRITE YOUR CODE BETWEEN THIS LINE...
 
-
+        sb.append("Hello, world!");
+        sb.deleteCharAt(5);
 
         // ...AND THIS LINE
 
@@ -71,7 +73,8 @@ public StringBuilder four() {
         // 2. After adding the message, replace the word "world" with the word "Java"
         // WRITE YOUR CODE BETWEEN THIS LINE...
 
-
+        sb.append("Hello, world!");
+        sb.replace(7, 12, "Java");
 
         // ...AND THIS LINE