diff --git a/Sprint-2/debug/address.js b/Sprint-2/debug/address.js
index 940a6af83..a3217b713 100644
--- a/Sprint-2/debug/address.js
+++ b/Sprint-2/debug/address.js
@@ -1,5 +1,6 @@
 // Predict and explain first...
-
+// the const is an object, not an array, so [0] in the console log isn't correc
+t
 // This code should log out the houseNumber from the address object
 // but it isn't working...
 // Fix anything that isn't working
@@ -9,7 +10,7 @@ const address = {
   street: "Imaginary Road",
   city: "Manchester",
   country: "England",
-  postcode: "XYZ 123",
+  postcode: "xyz 123",
 };
 
-console.log(`My house number is ${address[0]}`);
+console.log(`my house number is ${address.houseNumber}`);
diff --git a/Sprint-2/debug/author.js b/Sprint-2/debug/author.js
index 8c2125977..3b3d1a776 100644
--- a/Sprint-2/debug/author.js
+++ b/Sprint-2/debug/author.js
@@ -1,5 +1,5 @@
 // Predict and explain first...
-
+// we should take the object and access to the values through dotation.
 // This program attempts to log out all the property values in the object.
 // But it isn't working. Explain why first and then fix the problem
 
@@ -11,6 +11,6 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
+for (const value of Object.values(author)) {
   console.log(value);
 }
diff --git a/Sprint-2/debug/recipe.js b/Sprint-2/debug/recipe.js
index 6cbdd22cd..6822a4e1f 100644
--- a/Sprint-2/debug/recipe.js
+++ b/Sprint-2/debug/recipe.js
@@ -10,6 +10,6 @@ const recipe = {
   ingredients: ["olive oil", "tomatoes", "salt", "pepper"],
 };
 
-console.log(`${recipe.title} serves ${recipe.serves}
-  ingredients:
-${recipe}`);
+console.log(`${recipe.title}`);
+console.log(`serves: ${recipe.serves}`);
+recipe.ingredients.forEach(i => console.log("-"+i));
\ No newline at end of file
diff --git a/Sprint-2/implement/contains.js b/Sprint-2/implement/contains.js
index cd779308a..9d23d92cf 100644
--- a/Sprint-2/implement/contains.js
+++ b/Sprint-2/implement/contains.js
@@ -1,3 +1,23 @@
-function contains() {}
+function contains(obj, prop) {
+
+    if (typeof obj !== "object" && obj === null ) { //typeof to check if the key is an object
+        return false;
+    } else if (Array.isArray(obj)) { //array.isarray to check that the obj is an array, so we throw an error message
+        throw new Error ("invalid input"); 
+    }
+
+    return prop in obj; //in method to check if a property is in the object
+
+}
+console.log(contains({ a: 1, b: 2 }, "a"));
+console.log(contains({ a: 1, b: 2 }, "c"));
+console.log(contains({}));
+console.log(contains({undefined},"b"));
+
+try {
+    console.log(contains([1, 2, 3], "3")); 
+}  catch (E) {
+    console.log(E.message);
+}
 
 module.exports = contains;
diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 326bdb1f2..a3170e07b 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -20,16 +20,28 @@ as the object doesn't contains a key of 'c'
 // Given an empty object
 // When passed to contains
 // Then it should return false
-test.todo("contains on empty object returns false");
+test("contains on empty object returns false", () => {
+    expect(contains({}, "a")).toBe(false);
+});
 
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
-
+test("contains return true for existing property", () => {
+    const obj = {a:5, b:10};
+    expect(contains(obj, "a")).toBe(true);
+});
 // Given an object with properties
 // When passed to contains with a non-existent property name
 // Then it should return false
-
+test("contains return false for a non-existent property", () => {
+    const obj = { a: 5, b: 10 }; 
+    expect(contains(obj, "d")).toBe(false);
+});
 // Given invalid parameters like an array
 // When passed to contains
 // Then it should return false or throw an error
+test("contains return throw an error message for invalid parameters like an array", () => {
+  const arr = ["a", "b", "c", "d"];
+  expect(() => contains(arr, "d")).toThrow("invalid input");
+});
\ No newline at end of file
diff --git a/Sprint-2/implement/lookup.js b/Sprint-2/implement/lookup.js
index a6746e07f..6a4466d7b 100644
--- a/Sprint-2/implement/lookup.js
+++ b/Sprint-2/implement/lookup.js
@@ -1,5 +1,12 @@
-function createLookup() {
-  // implementation here
-}
+function createLookup(codePairs) {
 
+  if (!Array.isArray(codePairs)) {
+    return null;
+  }
+
+  return Object.fromEntries(codePairs); //convert the code pairs arrays into object
+
+} 
+
+    
 module.exports = createLookup;
diff --git a/Sprint-2/implement/lookup.test.js b/Sprint-2/implement/lookup.test.js
index 547e06c5a..eae40a747 100644
--- a/Sprint-2/implement/lookup.test.js
+++ b/Sprint-2/implement/lookup.test.js
@@ -1,7 +1,5 @@
 const createLookup = require("./lookup.js");
 
-test.todo("creates a country currency code lookup for multiple codes");
-
 /*
 
 Create a lookup object of key value pairs from an array of code pairs
@@ -33,3 +31,29 @@ It should return:
    'CA': 'CAD'
  }
 */
+
+test("returns empty object when passed an empty array", () => {
+  expect(createLookup([])).toEqual({});
+});
+
+test("returns null when passed a non-array input", () => {
+  expect(createLookup("hello")).toBeNull();
+  expect(createLookup({})).toBeNull();
+  expect(createLookup(123)).toBeNull();
+});
+
+test("creates a lookup object from an array of code pairs", () => {
+  const countryCurrency = [
+    ["US", "USD"],
+    ["CA", "CAD"],
+    ["MX", "MXN"],
+  ];
+
+  const expected = {
+    US: "USD",
+    CA: "CAD",
+    MX: "MXN",
+  };
+
+  expect(createLookup(countryCurrency)).toEqual(expected);
+});
\ No newline at end of file
diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 45ec4e5f3..b1ccb095f 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -6,11 +6,12 @@ function parseQueryString(queryString) {
   const keyValuePairs = queryString.split("&");
 
   for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
+    const [key, ...rest] = pair.split("="); //split the first = from the key 
+    const value = rest.join("="); //join the value
     queryParams[key] = value;
-  }
+  } 
 
   return queryParams;
-}
+} 
 
 module.exports = parseQueryString;
diff --git a/Sprint-2/implement/querystring.test.js b/Sprint-2/implement/querystring.test.js
index 3e218b789..2f120598f 100644
--- a/Sprint-2/implement/querystring.test.js
+++ b/Sprint-2/implement/querystring.test.js
@@ -10,3 +10,15 @@ test("parses querystring values containing =", () => {
     "equation": "x=y+1",
   });
 });
+
+test("multiple key-value pairs", () => {
+  expect(parseQueryString("a=1&b=2")).toEqual({ a: "1", b: "2" });
+});
+
+test("only = character", () => {
+  expect(parseQueryString("=")).toEqual({ "": "" });
+});
+
+test("empty key with value", () => {
+  expect(parseQueryString("=value")).toEqual({ "": "value" });
+});
diff --git a/Sprint-2/implement/tally.js b/Sprint-2/implement/tally.js
index f47321812..a9e53d26a 100644
--- a/Sprint-2/implement/tally.js
+++ b/Sprint-2/implement/tally.js
@@ -1,3 +1,22 @@
-function tally() {}
+function tally(arr) {
+  
+    if (!Array.isArray(arr)) {
+      throw new TypeError("Input must be an array");
+    }  
+    
+    const counts = {}; //store the result as an object 
+
+      for (const items of arr) { //for... of loop to count the items 
+        if (counts[items]) {
+          counts[items] += 1;
+        } else {
+          counts[items] = 1;
+        }
+      }  
+
+    return counts;
+
+}
+
 
 module.exports = tally;
diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index 2ceffa8dd..019ffdf97 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -19,16 +19,29 @@ const tally = require("./tally.js");
 // Given a function called tally
 // When passed an array of items
 // Then it should return an object containing the count for each unique item
-
+test("return an object containing the count for each unique item", () => {
+    const arr = ["a", "a", "b", "c"];
+    const expected = { a: 2, b: 1, c: 1 };
+    expect(tally(arr)).toEqual(expected);
+});
 // Given an empty array
 // When passed to tally
 // Then it should return an empty object
-test.todo("tally on an empty array returns an empty object");
+test("should return an empty object for an empty array input", () => {
+    expect(tally([])).toEqual({});
+});
 
 // Given an array with duplicate items
 // When passed to tally
 // Then it should return counts for each unique item
-
+test("should return an object with the counts of each unique item for an input with duplicates", () => {
+    const dup = ["a", "a", "c"];
+    const expected = {a:2, c:1};
+    expect(tally(dup)).toEqual(expected);
+});
 // Given an invalid input like a string
 // When passed to tally
 // Then it should throw an error
+test("throw an error given a valid input like a string", () => {
+    expect(() => tally("hello")).toThrow("Input must be an array");
+});
\ No newline at end of file
diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index bb353fb1f..dd6afadeb 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -10,20 +10,34 @@ function invert(obj) {
   const invertedObj = {};
 
   for (const [key, value] of Object.entries(obj)) {
-    invertedObj.key = value;
+    invertedObj[value] = key;
   }
 
   return invertedObj;
 }
 
-// a) What is the current return value when invert is called with { a : 1 }
+// a) What is the current return value when invert is called with { a : 1 } = { key : 1}
 
-// b) What is the current return value when invert is called with { a: 1, b: 2 }
+// b) What is the current return value when invert is called with { a: 1, b: 2 } = { key : 2}
 
-// c) What is the target return value when invert is called with {a : 1, b: 2}
+// c) What is the target return value when invert is called with {a : 1, b: 2} = { 1 : a, 2 : b}
 
-// c) What does Object.entries return? Why is it needed in this program?
+// c) What does Object.entries return? Why is it needed in this program? = returns an array of key, value pairs. It's important bc we can loop both, key and values.
 
-// d) Explain why the current return value is different from the target output
+// d) Explain why the current return value is different from the target output = because invertedObj.key is just setting a property called "key" 
+// we need to use the [] to access to the variable.
+
+// e) Fix the implementation of invert (and write tests to prove it's fixed!) 
+
+test("inverts object with numeric strings value", () => {
+  expect(invert({ "a": 1, "b": 2 })).toEqual({ 1: "a", 2: "b" });
+});
+
+test("inverts object with strings value", () => {
+  expect(invert({ "a": "hello", "b": "world" })).toEqual({ "hello": "a", "world": "b" });
+});
+
+test("inverts object with numeric strings value and literal strings value", () => {
+  expect(invert({ "a": "hello", "b": 5 })).toEqual({ hello: "a", 5 : "b" });
+});
 
-// e) Fix the implementation of invert (and write tests to prove it's fixed!)
diff --git a/Sprint-3/prep/exerciseprep.html b/Sprint-3/prep/exerciseprep.html
new file mode 100644
index 000000000..a3bef2628
--- /dev/null
+++ b/Sprint-3/prep/exerciseprep.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Document</title>
+  </head>
+  <body>
+    <section>
+      <h3>Character limit</h3>
+      <label for="comment-input">
+        Please enter your comment in the text area below
+      </label>
+      <textarea
+        id="comment-input"
+        name="comment-input"
+        rows="5"
+        maxlength="200"
+      ></textarea>
+      <p id="character-limit-info">You have 200 characters remaining</p>
+    </section>
+    <script src="script.js"></script>
+  </body>
+</html>
\ No newline at end of file
diff --git a/Sprint-3/prep/script.js b/Sprint-3/prep/script.js
new file mode 100644
index 000000000..91efa7c64
--- /dev/null
+++ b/Sprint-3/prep/script.js
@@ -0,0 +1,13 @@
+  //select the elements from the html file with query selector calling the id (#)
+  const textarea = document.querySelector("#comment-input");
+  const info = document.querySelector("#character-limit-info");
+//get the limit of characters 
+  const maxLength = Number(textarea.getAttribute("maxlength"));
+// add the event listener with the "input" for typing in a text field.
+  textarea.addEventListener("input", () => {
+    const typed = textarea.value.length;
+    const remaining = maxLength - typed;
+    //create the string and print the result of the remaining characters
+    info.textContent = `You have ${remaining} characters remaining`;
+  });
+
diff --git a/Sprint-3/slideshow/readme.md b/Sprint-3/slideshow/readme.md
index a0c06e4ff..c4645f630 100644
--- a/Sprint-3/slideshow/readme.md
+++ b/Sprint-3/slideshow/readme.md
@@ -6,8 +6,7 @@ First off, once you've branched off `main`, then update the title element in `in
 
 Make a website which allows the user to navigate a set of images (first manually, then with an auto-playing slideshow).
 
-[Try this live demo!](https://cyf-image-carousel.netlify.app/)
-
+[Try this live demo!]heck link in original repository
 # Level 1 Challenge
 
 Make forward and back buttons to move _manually_ in that direction through a list of at least 4 images.