diff --git a/Sprint-2/debug/address.js b/Sprint-2/debug/address.js
index 940a6af83..34aa6c9ea 100644
--- a/Sprint-2/debug/address.js
+++ b/Sprint-2/debug/address.js
@@ -1,5 +1,7 @@
 // Predict and explain first...
 
+// Adress is not an array its an object, objects use key values so [0] is an array not a key value for a houseNumber.
+
 // This code should log out the houseNumber from the address object
 // but it isn't working...
 // Fix anything that isn't working
@@ -12,4 +14,4 @@ const address = {
   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..b40a7da95 100644
--- a/Sprint-2/debug/author.js
+++ b/Sprint-2/debug/author.js
@@ -1,4 +1,5 @@
 // Predict and explain first...
+//The code fails because:for...of only works with iterable objects,Plain JavaScript objects,which is author here,are not iterable.
 
 // 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 +12,6 @@ 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..533ac4ec5 100644
--- a/Sprint-2/debug/recipe.js
+++ b/Sprint-2/debug/recipe.js
@@ -11,5 +11,7 @@ const recipe = {
 };
 
 console.log(`${recipe.title} serves ${recipe.serves}
-  ingredients:
-${recipe}`);
+  ingredients:`);
+for (const ingredient of recipe.ingredients) {
+  console.log(ingredient);
+}
diff --git a/Sprint-2/implement/contains.js b/Sprint-2/implement/contains.js
index cd779308a..03a53a805 100644
--- a/Sprint-2/implement/contains.js
+++ b/Sprint-2/implement/contains.js
@@ -1,3 +1,21 @@
-function contains() {}
+function contains(obj, prop) {
+  if (obj === null) {
+    return false;
+  }
+
+  if (typeof obj !== "object") {
+    return false;
+  }
+
+  if (Array.isArray(obj)) {
+    return false;
+  }
+
+  if (prop in obj) {
+    return true;
+  } else {
+    return false;
+  }
+}
 
 module.exports = contains;
diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 326bdb1f2..0f8470140 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -1,35 +1,28 @@
 const contains = require("./contains.js");
 
-/*
-Implement a function called contains that checks an object contains a
-particular property
-
-E.g. contains({a: 1, b: 2}, 'a') // returns true
-as the object contains a key of 'a'
-
-E.g. contains({a: 1, b: 2}, 'c') // returns false
-as the object doesn't contains a key of 'c'
-*/
-
-// Acceptance criteria:
-
-// Given a contains function
-// When passed an object and a property name
-// Then it should return true if the object contains the property, false otherwise
-
-// Given an empty object
-// When passed to contains
-// Then it should return false
-test.todo("contains on empty object returns false");
-
-// Given an object with properties
-// When passed to contains with an existing property name
-// Then it should return true
-
-// Given an object with properties
-// When passed to contains with a non-existent property name
-// Then it should return false
-
-// Given invalid parameters like an array
-// When passed to contains
-// Then it should return false or throw an error
+describe("contains", () => {
+  test("returns false for an empty object", () => {
+    expect(contains({}, "a")).toBe(false);
+  });
+
+  test("returns true when object contains the property", () => {
+    expect(contains({ a: 1, b: 2 }, "a")).toBe(true);
+  });
+
+  test("returns false when object does not contain the property", () => {
+    expect(contains({ a: 1, b: 2 }, "c")).toBe(false);
+  });
+
+  test("returns false when given an array instead of an object", () => {
+    expect(contains([], "a")).toBe(false);
+  });
+
+  test("returns false when given null", () => {
+    expect(contains(null, "a")).toBe(false);
+  });
+
+  test("returns false when given a non-object type", () => {
+    expect(contains(42, "a")).toBe(false);
+    expect(contains("string", "a")).toBe(false);
+  });
+});
\ No newline at end of file
diff --git a/Sprint-2/implement/lookup.js b/Sprint-2/implement/lookup.js
index a6746e07f..0611a334f 100644
--- a/Sprint-2/implement/lookup.js
+++ b/Sprint-2/implement/lookup.js
@@ -1,5 +1,18 @@
-function createLookup() {
-  // implementation here
+function createLookup(pairs) {
+  if (!Array.isArray(pairs)) {
+    return {};
+  }
+
+  const lookup = {};
+
+  for (const pair of pairs) {
+    if (Array.isArray(pair) && pair.length === 2) {
+      const [country, currency] = pair;
+      lookup[country] = currency;
+    }
+  }
+
+  return lookup;
 }
 
 module.exports = createLookup;
diff --git a/Sprint-2/implement/lookup.test.js b/Sprint-2/implement/lookup.test.js
index 547e06c5a..b9c506d72 100644
--- a/Sprint-2/implement/lookup.test.js
+++ b/Sprint-2/implement/lookup.test.js
@@ -1,6 +1,60 @@
 const createLookup = require("./lookup.js");
 
-test.todo("creates a country currency code lookup for multiple codes");
+describe("createLookup", () => {
+  test("creates a country currency code lookup for multiple codes", () => {
+    const input = [
+      ["US", "USD"],
+      ["CA", "CAD"],
+    ];
+    const result = createLookup(input);
+
+    expect(result).toEqual({
+      US: "USD",
+      CA: "CAD",
+    });
+  });
+
+  test("returns empty object for empty array", () => {
+    expect(createLookup([])).toEqual({});
+  });
+
+  test("handles a single pair", () => {
+    const input = [["GB", "GBP"]];
+    expect(createLookup(input)).toEqual({
+      GB: "GBP",
+    });
+  });
+
+  test("ignores invalid pairs (not arrays)", () => {
+    const input = [["US", "USD"], "invalid", null];
+    expect(createLookup(input)).toEqual({
+      US: "USD",
+    });
+  });
+
+  test("ignores pairs that do not have exactly two elements", () => {
+    const input = [["US", "USD"], ["CA"], ["MX", "MXN", "extra"]];
+    expect(createLookup(input)).toEqual({
+      US: "USD",
+    });
+  });
+
+  test("overwrites duplicate country codes with the latest value", () => {
+    const input = [
+      ["US", "USD"],
+      ["US", "USN"],
+    ];
+    expect(createLookup(input)).toEqual({
+      US: "USN",
+    });
+  });
+
+  test("returns empty object for invalid input (not an array)", () => {
+    expect(createLookup(null)).toEqual({});
+    expect(createLookup({})).toEqual({});
+    expect(createLookup("string")).toEqual({});
+  });
+});
 
 /*
 
@@ -21,6 +75,7 @@ Then
  - The values are the corresponding currency codes
 
 Example
+
 Given: [['US', 'USD'], ['CA', 'CAD']]
 
 When
diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 45ec4e5f3..2c34b052c 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -1,16 +1,34 @@
+
 function parseQueryString(queryString) {
   const queryParams = {};
-  if (queryString.length === 0) {
+
+  if (!queryString || typeof queryString !== "string") {
     return queryParams;
   }
+
   const keyValuePairs = queryString.split("&");
 
   for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
-    queryParams[key] = value;
+    if (!pair) continue;
+
+    const index = pair.indexOf("=");
+
+    let key, value;
+
+    if (index === -1) {
+      key = pair;
+      value = "";
+    } else {
+      key = pair.slice(0, index);
+      value = pair.slice(index + 1);
+    }
+
+    if (key) {
+      queryParams[key] = value;
+    }
   }
 
   return queryParams;
 }
 
-module.exports = parseQueryString;
+module.exports = parseQueryString;
\ No newline at end of file
diff --git a/Sprint-2/implement/querystring.test.js b/Sprint-2/implement/querystring.test.js
index 3e218b789..f640ce7ec 100644
--- a/Sprint-2/implement/querystring.test.js
+++ b/Sprint-2/implement/querystring.test.js
@@ -3,10 +3,59 @@
 // Below is one test case for an edge case the implementation doesn't handle well.
 // Fix the implementation for this test, and try to think of as many other edge cases as possible - write tests and fix those too.
 
-const parseQueryString = require("./querystring.js")
+const parseQueryString = require("./querystring.js");
 
 test("parses querystring values containing =", () => {
   expect(parseQueryString("equation=x=y+1")).toEqual({
-    "equation": "x=y+1",
+    equation: "x=y+1",
+  });
+});
+
+describe("parseQueryString edge cases", () => {
+  test("returns empty object for empty string", () => {
+    expect(parseQueryString("")).toEqual({});
+  });
+
+  test("handles multiple key value pairs", () => {
+    expect(parseQueryString("a=1&b=2")).toEqual({
+      a: "1",
+      b: "2",
+    });
+  });
+
+  test("handles missing value", () => {
+    expect(parseQueryString("a=")).toEqual({
+      a: "",
+    });
+  });
+
+  test("handles missing equals sign", () => {
+    expect(parseQueryString("a")).toEqual({
+      a: "",
+    });
+  });
+
+  test("handles multiple equals signs in value", () => {
+    expect(parseQueryString("a=1=2=3")).toEqual({
+      a: "1=2=3",
+    });
+  });
+
+  test("ignores empty pairs", () => {
+    expect(parseQueryString("a=1&&b=2")).toEqual({
+      a: "1",
+      b: "2",
+    });
+  });
+
+  test("overwrites duplicate keys with last value", () => {
+    expect(parseQueryString("a=1&a=2")).toEqual({
+      a: "2",
+    });
+  });
+
+  test("returns empty object for invalid input", () => {
+    expect(parseQueryString(null)).toEqual({});
+    expect(parseQueryString(undefined)).toEqual({});
   });
 });
diff --git a/Sprint-2/implement/tally.js b/Sprint-2/implement/tally.js
index f47321812..459a301c7 100644
--- a/Sprint-2/implement/tally.js
+++ b/Sprint-2/implement/tally.js
@@ -1,3 +1,15 @@
-function tally() {}
+function tally(items) {
+  if (!Array.isArray(items)) {
+    throw new Error("Input must be an array");
+  }
+
+  const counts = {};
+
+  for (const item of items) {
+    counts[item] = (counts[item] || 0) + 1;
+  }
+
+  return counts;
+}
 
 module.exports = tally;
diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index 2ceffa8dd..4c0afac3f 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -1,34 +1,31 @@
 const tally = require("./tally.js");
 
-/**
- * tally array
- *
- * In this task, you'll need to implement a function called tally
- * that will take a list of items and count the frequency of each item
- * in an array
- *
- * For example:
- *
- * tally(['a']), target output: { a: 1 }
- * tally(['a', 'a', 'a']), target output: { a: 3 }
- * tally(['a', 'a', 'b', 'c']), target output: { a : 2, b: 1, c: 1 }
- */
+describe("tally", () => {
+  test("tally on an empty array returns an empty object", () => {
+    expect(tally([])).toEqual({});
+  });
 
-// Acceptance criteria:
+  test("counts duplicate items correctly", () => {
+    expect(tally(["a", "a", "b", "c"])).toEqual({
+      a: 2,
+      b: 1,
+      c: 1,
+    });
+  });
 
-// 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("counts single item array", () => {
+    expect(tally(["a"])).toEqual({ a: 1 });
+  });
 
-// 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("counts all same items", () => {
+    expect(tally(["a", "a", "a"])).toEqual({ a: 3 });
+  });
 
-// Given an array with duplicate items
-// When passed to tally
-// Then it should return counts for each unique item
+  test("throws error for invalid input (string)", () => {
+    expect(() => tally("abc")).toThrow("Input must be an array");
+  });
 
-// Given an invalid input like a string
-// When passed to tally
-// Then it should throw an error
+  test("throws error for invalid input (null)", () => {
+    expect(() => tally(null)).toThrow("Input must be an array");
+  });
+});
diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index bb353fb1f..14271d306 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -17,13 +17,30 @@ function invert(obj) {
 }
 
 // a) What is the current return value when invert is called with { a : 1 }
+// { key: 1 } Because `invertedObj.key = value` uses the literal string "key" instead of the variable `key`.
 
 // b) What is the current return value when invert is called with { a: 1, b: 2 }
+// { key: 2 } Each iteration overwrites the same "key" property, so only the last value remains.
 
-// 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?
+// d) What does Object.entries return? Why is it needed in this program?
+// Object.entries(obj) returns an array of [key, value] pairs: [["a",1], ["b",2]] This allows us to easily iterate over each key-value pair and swap them (key becomes value, value becomes key).
 
-// d) Explain why the current return value is different from the target output
+//e) Explain why the current return value is different from the target output
+// Because the original code uses a fixed string property (`invertedObj.key = value`) instead of using the dynamic variable `key`.
+// This overwrites the same property and doesn’t produce the correct inverted object.
 
-// e) Fix the implementation of invert (and write tests to prove it's fixed!)
+// f) Fix the implementation of invert (and write tests to prove it's fixed!)
+// See below:
+
+// function invert(obj) {
+//   const invertedObj = {};
+
+//   for (const [key, value] of Object.entries(obj)) {
+//     invertedObj[value] = key; // dynamic key assignment
+//   }
+
+//   return invertedObj;
+// }
diff --git a/Sprint-2/package-lock.json b/Sprint-2/package-lock.json
index 9b4c725d6..d636b043b 100644
--- a/Sprint-2/package-lock.json
+++ b/Sprint-2/package-lock.json
@@ -27,14 +27,14 @@
       }
     },
     "node_modules/@babel/code-frame": {
-      "version": "7.25.7",
-      "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.25.7.tgz",
-      "integrity": "sha512-0xZJFNE5XMpENsgfHYTw8FbX4kv53mFLn2i3XPoq69LyhYSCBJtitaHx9QnsVTrsogI4Z3+HtEfZ2/GFPOtf5g==",
+      "version": "7.29.0",
+      "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.29.0.tgz",
+      "integrity": "sha512-9NhCeYjq9+3uxgdtp20LSiJXJvN0FeCtNGpJxuMFZ1Kv3cWUNb6DOhJwUvcVCzKGR66cw4njwM6hrJLqgOwbcw==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
-        "@babel/highlight": "^7.25.7",
-        "picocolors": "^1.0.0"
+        "@babel/helper-validator-identifier": "^7.28.5",
+        "js-tokens": "^4.0.0",
+        "picocolors": "^1.1.1"
       },
       "engines": {
         "node": ">=6.9.0"
@@ -172,21 +172,19 @@
       }
     },
     "node_modules/@babel/helper-string-parser": {
-      "version": "7.25.7",
-      "resolved": "https://registry.npmjs.org/@babel/helper-string-parser/-/helper-string-parser-7.25.7.tgz",
-      "integrity": "sha512-CbkjYdsJNHFk8uqpEkpCvRs3YRp9tY6FmFY7wLMSYuGYkrdUi7r2lc4/wqsvlHoMznX3WJ9IP8giGPq68T/Y6g==",
+      "version": "7.27.1",
+      "resolved": "https://registry.npmjs.org/@babel/helper-string-parser/-/helper-string-parser-7.27.1.tgz",
+      "integrity": "sha512-qMlSxKbpRlAridDExk92nSobyDdpPijUq2DW6oDnUqd0iOGxmQjyqhMIihI9+zv4LPyZdRje2cavWPbCbWm3eA==",
       "dev": true,
-      "license": "MIT",
       "engines": {
         "node": ">=6.9.0"
       }
     },
     "node_modules/@babel/helper-validator-identifier": {
-      "version": "7.25.7",
-      "resolved": "https://registry.npmjs.org/@babel/helper-validator-identifier/-/helper-validator-identifier-7.25.7.tgz",
-      "integrity": "sha512-AM6TzwYqGChO45oiuPqwL2t20/HdMC1rTPAesnBCgPCSF1x3oN9MVUwQV2iyz4xqWrctwK5RNC8LV22kaQCNYg==",
+      "version": "7.28.5",
+      "resolved": "https://registry.npmjs.org/@babel/helper-validator-identifier/-/helper-validator-identifier-7.28.5.tgz",
+      "integrity": "sha512-qSs4ifwzKJSV39ucNjsvc6WVHs6b7S03sOh2OcHF9UHfVPqWWALUsNUVzhSBiItjRZoLHx7nIarVjqKVusUZ1Q==",
       "dev": true,
-      "license": "MIT",
       "engines": {
         "node": ">=6.9.0"
       }
@@ -202,121 +200,25 @@
       }
     },
     "node_modules/@babel/helpers": {
-      "version": "7.25.7",
-      "resolved": "https://registry.npmjs.org/@babel/helpers/-/helpers-7.25.7.tgz",
-      "integrity": "sha512-Sv6pASx7Esm38KQpF/U/OXLwPPrdGHNKoeblRxgZRLXnAtnkEe4ptJPDtAZM7fBLadbc1Q07kQpSiGQ0Jg6tRA==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "@babel/template": "^7.25.7",
-        "@babel/types": "^7.25.7"
-      },
-      "engines": {
-        "node": ">=6.9.0"
-      }
-    },
-    "node_modules/@babel/highlight": {
-      "version": "7.25.7",
-      "resolved": "https://registry.npmjs.org/@babel/highlight/-/highlight-7.25.7.tgz",
-      "integrity": "sha512-iYyACpW3iW8Fw+ZybQK+drQre+ns/tKpXbNESfrhNnPLIklLbXr7MYJ6gPEd0iETGLOK+SxMjVvKb/ffmk+FEw==",
+      "version": "7.29.2",
+      "resolved": "https://registry.npmjs.org/@babel/helpers/-/helpers-7.29.2.tgz",
+      "integrity": "sha512-HoGuUs4sCZNezVEKdVcwqmZN8GoHirLUcLaYVNBK2J0DadGtdcqgr3BCbvH8+XUo4NGjNl3VOtSjEKNzqfFgKw==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
-        "@babel/helper-validator-identifier": "^7.25.7",
-        "chalk": "^2.4.2",
-        "js-tokens": "^4.0.0",
-        "picocolors": "^1.0.0"
+        "@babel/template": "^7.28.6",
+        "@babel/types": "^7.29.0"
       },
       "engines": {
         "node": ">=6.9.0"
       }
     },
-    "node_modules/@babel/highlight/node_modules/ansi-styles": {
-      "version": "3.2.1",
-      "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-3.2.1.tgz",
-      "integrity": "sha512-VT0ZI6kZRdTh8YyJw3SMbYm/u+NqfsAxEpWO0Pf9sq8/e94WxxOpPKx9FR1FlyCtOVDNOQ+8ntlqFxiRc+r5qA==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "color-convert": "^1.9.0"
-      },
-      "engines": {
-        "node": ">=4"
-      }
-    },
-    "node_modules/@babel/highlight/node_modules/chalk": {
-      "version": "2.4.2",
-      "resolved": "https://registry.npmjs.org/chalk/-/chalk-2.4.2.tgz",
-      "integrity": "sha512-Mti+f9lpJNcwF4tWV8/OrTTtF1gZi+f8FqlyAdouralcFWFQWF2+NgCHShjkCb+IFBLq9buZwE1xckQU4peSuQ==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "ansi-styles": "^3.2.1",
-        "escape-string-regexp": "^1.0.5",
-        "supports-color": "^5.3.0"
-      },
-      "engines": {
-        "node": ">=4"
-      }
-    },
-    "node_modules/@babel/highlight/node_modules/color-convert": {
-      "version": "1.9.3",
-      "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
-      "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "color-name": "1.1.3"
-      }
-    },
-    "node_modules/@babel/highlight/node_modules/color-name": {
-      "version": "1.1.3",
-      "resolved": "https://registry.npmjs.org/color-name/-/color-name-1.1.3.tgz",
-      "integrity": "sha512-72fSenhMw2HZMTVHeCA9KCmpEIbzWiQsjN+BHcBbS9vr1mtt+vJjPdksIBNUmKAW8TFUDPJK5SUU3QhE9NEXDw==",
-      "dev": true,
-      "license": "MIT"
-    },
-    "node_modules/@babel/highlight/node_modules/escape-string-regexp": {
-      "version": "1.0.5",
-      "resolved": "https://registry.npmjs.org/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz",
-      "integrity": "sha512-vbRorB5FUQWvla16U8R/qgaFIya2qGzwDrNmCZuYKrbdSUMG6I1ZCGQRefkRVhuOkIGVne7BQ35DSfo1qvJqFg==",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": ">=0.8.0"
-      }
-    },
-    "node_modules/@babel/highlight/node_modules/has-flag": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/has-flag/-/has-flag-3.0.0.tgz",
-      "integrity": "sha512-sKJf1+ceQBr4SMkvQnBDNDtf4TXpVhVGateu0t918bl30FnbE2m4vNLX+VWe/dpjlb+HugGYzW7uQXH98HPEYw==",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": ">=4"
-      }
-    },
-    "node_modules/@babel/highlight/node_modules/supports-color": {
-      "version": "5.5.0",
-      "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-5.5.0.tgz",
-      "integrity": "sha512-QjVjwdXIt408MIiAqCX4oUKsgU2EqAGzs2Ppkm4aQYbjm+ZEWEcW4SfFNTr4uMNZma0ey4f5lgLrkB0aX0QMow==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "has-flag": "^3.0.0"
-      },
-      "engines": {
-        "node": ">=4"
-      }
-    },
     "node_modules/@babel/parser": {
-      "version": "7.25.8",
-      "resolved": "https://registry.npmjs.org/@babel/parser/-/parser-7.25.8.tgz",
-      "integrity": "sha512-HcttkxzdPucv3nNFmfOOMfFf64KgdJVqm1KaCm25dPGMLElo9nsLvXeJECQg8UzPuBGLyTSA0ZzqCtDSzKTEoQ==",
+      "version": "7.29.2",
+      "resolved": "https://registry.npmjs.org/@babel/parser/-/parser-7.29.2.tgz",
+      "integrity": "sha512-4GgRzy/+fsBa72/RZVJmGKPmZu9Byn8o4MoLpmNe1m8ZfYnz5emHLQz3U4gLud6Zwl0RZIcgiLD7Uq7ySFuDLA==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
-        "@babel/types": "^7.25.8"
+        "@babel/types": "^7.29.0"
       },
       "bin": {
         "parser": "bin/babel-parser.js"
@@ -565,15 +467,14 @@
       }
     },
     "node_modules/@babel/template": {
-      "version": "7.25.7",
-      "resolved": "https://registry.npmjs.org/@babel/template/-/template-7.25.7.tgz",
-      "integrity": "sha512-wRwtAgI3bAS+JGU2upWNL9lSlDcRCqD05BZ1n3X2ONLH1WilFP6O1otQjeMK/1g0pvYcXC7b/qVUB1keofjtZA==",
+      "version": "7.28.6",
+      "resolved": "https://registry.npmjs.org/@babel/template/-/template-7.28.6.tgz",
+      "integrity": "sha512-YA6Ma2KsCdGb+WC6UpBVFJGXL58MDA6oyONbjyF/+5sBgxY/dwkhLogbMT2GXXyU84/IhRw/2D1Os1B/giz+BQ==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
-        "@babel/code-frame": "^7.25.7",
-        "@babel/parser": "^7.25.7",
-        "@babel/types": "^7.25.7"
+        "@babel/code-frame": "^7.28.6",
+        "@babel/parser": "^7.28.6",
+        "@babel/types": "^7.28.6"
       },
       "engines": {
         "node": ">=6.9.0"
@@ -599,15 +500,13 @@
       }
     },
     "node_modules/@babel/types": {
-      "version": "7.25.8",
-      "resolved": "https://registry.npmjs.org/@babel/types/-/types-7.25.8.tgz",
-      "integrity": "sha512-JWtuCu8VQsMladxVz/P4HzHUGCAwpuqacmowgXFs5XjxIgKuNjnLokQzuVjlTvIzODaDmpjT3oxcC48vyk9EWg==",
+      "version": "7.29.0",
+      "resolved": "https://registry.npmjs.org/@babel/types/-/types-7.29.0.tgz",
+      "integrity": "sha512-LwdZHpScM4Qz8Xw2iKSzS+cfglZzJGvofQICy7W7v4caru4EaAmyUuO6BGrbyQ2mYV11W0U8j5mBhd14dd3B0A==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
-        "@babel/helper-string-parser": "^7.25.7",
-        "@babel/helper-validator-identifier": "^7.25.7",
-        "to-fast-properties": "^2.0.0"
+        "@babel/helper-string-parser": "^7.27.1",
+        "@babel/helper-validator-identifier": "^7.28.5"
       },
       "engines": {
         "node": ">=6.9.0"
@@ -1325,11 +1224,10 @@
       "license": "MIT"
     },
     "node_modules/brace-expansion": {
-      "version": "1.1.11",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
-      "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
+      "version": "1.1.12",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.12.tgz",
+      "integrity": "sha512-9T9UjW3r0UW5c1Q7GTwllptXwhvYmEzFhzMfZ9H7FQWt+uZePjZPjBP/W1ZEyZ1twGWom5/56TF4lPcqjnDHcg==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
         "balanced-match": "^1.0.0",
         "concat-map": "0.0.1"
@@ -1579,11 +1477,10 @@
       }
     },
     "node_modules/cross-spawn": {
-      "version": "7.0.3",
-      "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.3.tgz",
-      "integrity": "sha512-iRDPJKUPVEND7dHPO8rkbOnPpyDygcDFtWjpeWNCgy8WP2rXcxXL8TskReQl6OrB2G7+UJrags1q15Fudc7G6w==",
+      "version": "7.0.6",
+      "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.6.tgz",
+      "integrity": "sha512-uV2QOWP2nWzsy2aMp8aRibhi9dlzF5Hgh5SHaB9OiTGEyDTiJJyx0uy51QXdyWbtAHNua4XJzUKca3OzKUd3vA==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
         "path-key": "^3.1.0",
         "shebang-command": "^2.0.0",
@@ -2781,15 +2678,13 @@
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-4.0.0.tgz",
       "integrity": "sha512-RdJUflcE3cUzKiMqQgsCu06FPu9UdIJO0beYbPhHN4k6apgJtifcoCtT9bcxOpYBtpD2kCM6Sbzg4CausW/PKQ==",
-      "dev": true,
-      "license": "MIT"
+      "dev": true
     },
     "node_modules/js-yaml": {
-      "version": "3.14.1",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.14.1.tgz",
-      "integrity": "sha512-okMH7OXXJ7YrN9Ok3/SXrnu4iX9yOk+25nqX4imS2npuvTYDmo/QEZoqwZkYaIDk3jVvBOTOIEgEhaLOynBS9g==",
+      "version": "3.14.2",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.14.2.tgz",
+      "integrity": "sha512-PMSmkqxr106Xa156c2M265Z+FTrPl+oxd/rgOQy2tijQeK5TxQ43psO1ZCwhVOSdnn+RzkzlRz/eY4BgJBYVpg==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
         "argparse": "^1.0.7",
         "esprima": "^4.0.0"
@@ -2952,11 +2847,10 @@
       }
     },
     "node_modules/minimatch": {
-      "version": "3.1.2",
-      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.1.2.tgz",
-      "integrity": "sha512-J7p63hRiAjw1NDEww1W7i37+ByIrOWO5XQQAzZ3VOcL0PNybwpfmV/N05zFAzwQ9USyEcX6t3UO+K5aqBQOIHw==",
+      "version": "3.1.5",
+      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.1.5.tgz",
+      "integrity": "sha512-VgjWUsnnT6n+NUk6eZq77zeFdpW2LWDzP6zFGrCbHXiYNul5Dzqk2HHQ5uFH2DNW5Xbp8+jVzaeNt94ssEEl4w==",
       "dev": true,
-      "license": "ISC",
       "dependencies": {
         "brace-expansion": "^1.1.7"
       },
@@ -3153,11 +3047,10 @@
       "license": "MIT"
     },
     "node_modules/picocolors": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.0.tgz",
-      "integrity": "sha512-TQ92mBOW0l3LeMeyLV6mzy/kWr8lkd/hp3mTg7wYK7zJhuBStmGMBG0BdeDZS/dZx1IukaX6Bk11zcln25o1Aw==",
-      "dev": true,
-      "license": "ISC"
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",
+      "integrity": "sha512-xceH2snhtb5M9liqDsmEw56le376mTZkEX/jEb/RxNFyegNul7eNslCXP9FDj/Lcu0X8KEyMceP2ntpaHrDEVA==",
+      "dev": true
     },
     "node_modules/picomatch": {
       "version": "2.3.1",
@@ -3543,16 +3436,6 @@
       "dev": true,
       "license": "BSD-3-Clause"
     },
-    "node_modules/to-fast-properties": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/to-fast-properties/-/to-fast-properties-2.0.0.tgz",
-      "integrity": "sha512-/OaKK0xYrs3DmxRYqL/yDc+FxFUVYhDlXMhRmv3z915w2HF1tnN1omB354j8VUGO/hbRzyD6Y3sA7v7GS/ceog==",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": ">=4"
-      }
-    },
     "node_modules/to-regex-range": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/to-regex-range/-/to-regex-range-5.0.1.tgz",
diff --git a/Sprint-2/stretch/count-words.js b/Sprint-2/stretch/count-words.js
index 8e85d19d7..e8a8927a9 100644
--- a/Sprint-2/stretch/count-words.js
+++ b/Sprint-2/stretch/count-words.js
@@ -26,3 +26,21 @@
 
 3. Order the results to find out which word is the most common in the input
 */
+
+function countWords(str) {
+  if (typeof str !== "string") {
+    throw new Error("Input must be a string");
+  }
+
+  const counts = {};
+  const words = str.split(/\s+/);
+
+  for (const word of words) {
+    if (word === "") continue;
+    counts[word] = (counts[word] || 0) + 1;
+  }
+
+  return counts;
+}
+
+module.exports = countWords;
diff --git a/Sprint-2/stretch/mode.js b/Sprint-2/stretch/mode.js
index 3f7609d79..9efce35f9 100644
--- a/Sprint-2/stretch/mode.js
+++ b/Sprint-2/stretch/mode.js
@@ -8,29 +8,34 @@
 // refactor calculateMode by splitting up the code
 // into smaller functions using the stages above
 
-function calculateMode(list) {
-  // track frequency of each value
-  let freqs = new Map();
-
-  for (let num of list) {
-    if (typeof num !== "number") {
-      continue;
-    }
+function trackFrequencies(list) {
+  const frequencies = new Map();
 
-    freqs.set(num, (freqs.get(num) || 0) + 1);
+  for (const num of list) {
+    if (typeof num !== "number") continue;
+    frequencies.set(num, (frequencies.get(num) || 0) + 1);
   }
 
-  // Find the value with the highest frequency
+  return frequencies;
+}
+
+function findMode(frequencies) {
   let maxFreq = 0;
   let mode;
-  for (let [num, freq] of freqs) {
+
+  for (const [num, freq] of frequencies) {
     if (freq > maxFreq) {
-      mode = num;
       maxFreq = freq;
+      mode = num;
     }
   }
 
   return maxFreq === 0 ? NaN : mode;
 }
 
+function calculateMode(list) {
+  const frequencies = trackFrequencies(list);
+  return findMode(frequencies);
+}
+
 module.exports = calculateMode;
diff --git a/Sprint-2/stretch/till.js b/Sprint-2/stretch/till.js
index 6a08532e7..b9624022d 100644
--- a/Sprint-2/stretch/till.js
+++ b/Sprint-2/stretch/till.js
@@ -8,10 +8,10 @@ function totalTill(till) {
   let total = 0;
 
   for (const [coin, quantity] of Object.entries(till)) {
-    total += coin * quantity;
+    const value = parseInt(coin); // "1p" → 1
+    total += value * quantity;
   }
-
-  return `£${total / 100}`;
+  return `£${(total / 100).toFixed(2)}`;
 }
 
 const till = {
@@ -22,10 +22,24 @@ const till = {
 };
 const totalAmount = totalTill(till);
 
-// a) What is the target output when totalTill is called with the till object
+module.exports = totalTill;
+
+// a) What is the target output when totalTill is called with the till object\
+// "£4.40"
+//  Explanation:
+//  1p * 10 = 10p
+//  5p * 6 = 30p
+//  50p * 4 = 200p
+//  20p * 10 = 200p
+//  Total = 440p → £4.40
 
 // b) Why do we need to use Object.entries inside the for...of loop in this function?
+// Object.entries(till) returns an array of [key, value] pairs. This allows us to iterate over both the coin type (key) and its quantity (value) easily.
 
 // c) What does coin * quantity evaluate to inside the for...of loop?
+// As currently written, coin is a string like "1p", "5p".
+// Multiplying a string by a number (e.g., "1p" * 10) results in NaN.
+// Therefore, we need to convert the string to a number first using parseInt(coin).
 
 // d) Write a test for this function to check it works and then fix the implementation of totalTill
+// See the test file till.test.js
diff --git a/Sprint-2/stretch/till.test.js b/Sprint-2/stretch/till.test.js
new file mode 100644
index 000000000..e8e4cf077
--- /dev/null
+++ b/Sprint-2/stretch/till.test.js
@@ -0,0 +1,21 @@
+const totalTill = require("./till.js");
+
+describe("totalTill", () => {
+  test("calculates total correctly", () => {
+    const till = {
+      "1p": 10,
+      "5p": 6,
+      "50p": 4,
+      "20p": 10,
+    };
+    expect(totalTill(till)).toBe("£4.40");
+  });
+
+  test("handles empty till", () => {
+    expect(totalTill({})).toBe("£0.00"); // now passes
+  });
+
+  test("handles single coin type", () => {
+    expect(totalTill({ "100p": 3 })).toBe("£3.00");
+  });
+});