diff --git a/src/__tests__/arrays.test.js b/src/__tests__/arrays.test.js
index d00a5566..7c9992da 100644
--- a/src/__tests__/arrays.test.js
+++ b/src/__tests__/arrays.test.js
@@ -19,7 +19,7 @@ const {
 describe('getNthElement', () => {
   const array = ['cat', 'dog', 'elephant', 'fox'];
 
-  xit('returns the element at the given position', () => {
+  it('returns the element at the given position', () => {
     expect(getNthElement(0, array)).toEqual('cat');
     expect(getNthElement(2, array)).toEqual('elephant');
     expect(getNthElement(3, array)).toEqual('fox');
diff --git a/src/__tests__/booleans.test.js b/src/__tests__/booleans.test.js
index 734201d5..4f794fc3 100644
--- a/src/__tests__/booleans.test.js
+++ b/src/__tests__/booleans.test.js
@@ -17,23 +17,23 @@ const {
 } = require('../booleans');
 
 describe('negate', () => {
-  xit('returns the opposite of the passed boolean value', () => {
+  it('returns the opposite of the passed boolean value', () => {
     expect(negate(true)).toBe(false);
     expect(negate(false)).toBe(true);
   });
 });
 
 describe('both', () => {
-  xit('returns true if both of the given booleans are true', () => {
+  it('returns true if both of the given booleans are true', () => {
     expect(both(true, true)).toBe(true);
     expect(both(true, false)).toBe(false);
     expect(both(false, true)).toBe(false);
     expect(both(false, false)).toBe(false);
   });
-});
+})
 
 describe('either', () => {
-  xit('returns true if at least one of the given booleans are true', () => {
+  it('returns true if at least one of the given booleans are true', () => {
     expect(either(true, true)).toBe(true);
     expect(either(true, false)).toBe(true);
     expect(either(false, true)).toBe(true);
@@ -42,7 +42,7 @@ describe('either', () => {
 });
 
 describe('none', () => {
-  xit('returns true if neither of the given booleans are true', () => {
+  it('returns true if neither of the given booleans are true', () => {
     expect(none(true, true)).toBe(false);
     expect(none(true, false)).toBe(false);
     expect(none(false, true)).toBe(false);
@@ -51,7 +51,7 @@ describe('none', () => {
 });
 
 describe('one', () => {
-  xit('returns true if exactly one of the given booleans are true', () => {
+  it('returns true if exactly one of the given booleans are true', () => {
     expect(one(true, true)).toBe(false);
     expect(one(true, false)).toBe(true);
     expect(one(false, true)).toBe(true);
@@ -74,7 +74,7 @@ describe('truthiness', () => {
 });
 
 describe('isEqual', () => {
-  xit('returns whether the two values are equal', () => {
+  it('returns whether the two values are equal', () => {
     expect(isEqual(true, false)).toBe(false);
     expect(isEqual(true, true)).toBe(true);
     expect(isEqual('true', 'true')).toBe(true);
@@ -86,7 +86,7 @@ describe('isEqual', () => {
 });
 
 describe('isGreaterThan', () => {
-  xit('returns true if the first number is strictly greater than the second', () => {
+  it('returns true if the first number is strictly greater than the second', () => {
     expect(isGreaterThan(1, 2)).toBe(false);
     expect(isGreaterThan(3, 2)).toBe(true);
     expect(isGreaterThan(4, 4)).toBe(false);
@@ -98,7 +98,7 @@ describe('isGreaterThan', () => {
 });
 
 describe('isLessThanOrEqualTo', () => {
-  xit('returns true if the first number is less than or equal to the second', () => {
+  it('returns true if the first number is less than or equal to the second', () => {
     expect(isLessThanOrEqualTo(1, 2)).toBe(true);
     expect(isLessThanOrEqualTo(3, 2)).toBe(false);
     expect(isLessThanOrEqualTo(4, 4)).toBe(true);
@@ -108,7 +108,7 @@ describe('isLessThanOrEqualTo', () => {
 });
 
 describe('isOdd', () => {
-  xit('returns whether the number is odd', () => {
+  it('returns whether the number is odd', () => {
     expect(isOdd(5)).toBe(true);
     expect(isOdd(6)).toBe(false);
     expect(isOdd(7)).toBe(true);
@@ -117,7 +117,7 @@ describe('isOdd', () => {
 });
 
 describe('isEven', () => {
-  xit('returns whether the number is even', () => {
+  it('returns whether the number is even', () => {
     expect(isEven(5)).toBe(false);
     expect(isEven(6)).toBe(true);
     expect(isEven(7)).toBe(false);
@@ -126,7 +126,7 @@ describe('isEven', () => {
 });
 
 describe('isSquare', () => {
-  xit('returns true if the number is a square', () => {
+  it('returns true if the number is a square', () => {
     expect(isSquare(9)).toEqual(true);
     expect(isSquare(4)).toEqual(true);
     expect(isSquare(5)).toEqual(false);
@@ -136,7 +136,7 @@ describe('isSquare', () => {
 });
 
 describe('startsWith', () => {
-  xit('returns whether the given string starts with the given character', () => {
+  it('returns whether the given string starts with the given character', () => {
     expect(startsWith('a', 'aardvark')).toBe(true);
     expect(startsWith('c', 'aardvark')).toBe(false);
     expect(startsWith('b', 'baardvark')).toBe(true);
@@ -146,7 +146,7 @@ describe('startsWith', () => {
 });
 
 describe('containsVowels', () => {
-  xit('returns whether the given string contains vowels', () => {
+  it('returns whether the given string contains vowels', () => {
     expect(containsVowels('cat')).toBe(true);
     expect(containsVowels('DOG')).toBe(true);
     expect(containsVowels('why')).toBe(false);
@@ -154,7 +154,7 @@ describe('containsVowels', () => {
 });
 
 describe('isLowerCase', () => {
-  xit('it returns true if the given string is lowercase', () => {
+  it('it returns true if the given string is lowercase', () => {
     expect(isLowerCase('abc')).toBe(true);
     expect(isLowerCase('abc213')).toBe(true);
     expect(isLowerCase('Abc')).toBe(false);
diff --git a/src/__tests__/numbers.test.js b/src/__tests__/numbers.test.js
index 253de15f..d610b3b3 100644
--- a/src/__tests__/numbers.test.js
+++ b/src/__tests__/numbers.test.js
@@ -13,7 +13,7 @@ const {
 } = require('../numbers');
 
 describe('add', () => {
-  xit('adds the two numbers together', () => {
+  it('adds the two numbers together', () => {
     expect(add(2, 1)).toEqual(3);
     expect(add(15, 76)).toEqual(91);
     expect(add(12, 0)).toEqual(12);
@@ -22,7 +22,7 @@ describe('add', () => {
 });
 
 describe('subtract', () => {
-  xit('subtracts the second number from the first', () => {
+  it('subtracts the second number from the first', () => {
     expect(subtract(2, 1)).toEqual(1);
     expect(subtract(1, 2)).toEqual(-1);
     expect(subtract(-2, 1)).toEqual(-3);
@@ -32,7 +32,7 @@ describe('subtract', () => {
 });
 
 describe('multiply', () => {
-  xit('multiplies the two numbers together', () => {
+  it('multiplies the two numbers together', () => {
     expect(multiply(10, 3)).toEqual(30);
     expect(multiply(-11, 5)).toEqual(-55);
     expect(multiply(-4, -9)).toEqual(36);
@@ -40,7 +40,7 @@ describe('multiply', () => {
 });
 
 describe('divide', () => {
-  xit('divides the first number by the second number', () => {
+  it('divides the first number by the second number', () => {
     expect(divide(20, 5)).toEqual(4);
     expect(divide(5, 2)).toEqual(2.5);
     expect(divide(2, 5)).toEqual(0.4);
@@ -49,7 +49,7 @@ describe('divide', () => {
 });
 
 describe('power', () => {
-  xit('returns the first number to the power of the second', () => {
+  it('returns the first number to the power of the second', () => {
     expect(power(5, 2)).toEqual(25);
     expect(power(2, 3)).toEqual(8);
     expect(power(10, 5)).toEqual(100000);
@@ -57,7 +57,7 @@ describe('power', () => {
 });
 
 describe('round', () => {
-  xit('rounds the number to the nearest integer', () => {
+  it('rounds the number to the nearest integer', () => {
     expect(round(2.1)).toEqual(2);
     expect(round(9.7)).toEqual(10);
     expect(round(5.5)).toEqual(6);
@@ -65,7 +65,7 @@ describe('round', () => {
 });
 
 describe('roundUp', () => {
-  xit('rounds the number up to the nearest integer', () => {
+  it('rounds the number up to the nearest integer', () => {
     expect(roundUp(2.1)).toEqual(3);
     expect(roundUp(9.7)).toEqual(10);
     expect(roundUp(5.5)).toEqual(6);
@@ -73,7 +73,7 @@ describe('roundUp', () => {
 });
 
 describe('roundDown', () => {
-  xit('rounds the number down to the nearest integer', () => {
+  it('rounds the number down to the nearest integer', () => {
     expect(roundDown(2.1)).toEqual(2);
     expect(roundDown(9.7)).toEqual(9);
     expect(roundDown(5.5)).toEqual(5);
@@ -81,7 +81,7 @@ describe('roundDown', () => {
 });
 
 describe('absolute', () => {
-  xit('returns the absolute value of the number', () => {
+  it('returns the absolute value of the number', () => {
     expect(absolute(-1)).toEqual(1);
     expect(absolute(1)).toEqual(1);
     expect(absolute(0)).toEqual(0);
@@ -93,7 +93,7 @@ describe('quotient', () => {
   // the first by the second, without the remainder
   // 18 divided by 7 is 2 remainder 4 (or 2.571...)
   // so the quotient of 18 and 7 is 2
-  xit('returns the quotient from dividing the first number by the second number', () => {
+  it('returns the quotient from dividing the first number by the second number', () => {
     expect(quotient(10, 3)).toEqual(3);
     expect(quotient(18, 7)).toEqual(2);
     expect(quotient(77, 10)).toEqual(7);
@@ -102,7 +102,7 @@ describe('quotient', () => {
 });
 
 describe('remainder', () => {
-  xit('returns the remainder when dividing the first number by the second number', () => {
+  it('returns the remainder when dividing the first number by the second number', () => {
     expect(remainder(10, 3)).toEqual(1);
     expect(remainder(18, 7)).toEqual(4);
     expect(remainder(77, 10)).toEqual(7);
diff --git a/src/__tests__/objects.test.js b/src/__tests__/objects.test.js
index 77abc373..ee72acb2 100644
--- a/src/__tests__/objects.test.js
+++ b/src/__tests__/objects.test.js
@@ -12,7 +12,7 @@ const {
 } = require('../objects');
 
 describe('createPerson', () => {
-  xit('creates an object with the given name and age properties', () => {
+  it('creates an object with the given name and age properties', () => {
     expect(createPerson('Fred', 79)).toEqual({
       name: 'Fred',
       age: 79
@@ -26,7 +26,7 @@ describe('createPerson', () => {
 });
 
 describe('getName', () => {
-  xit('returns the name property of the object', () => {
+  it('returns the name property of the object', () => {
     expect(
       getName({
         name: 'Fred',
@@ -43,7 +43,7 @@ describe('getName', () => {
 });
 
 describe('getProperty', () => {
-  xit('returns the given property', () => {
+  it('returns the given property', () => {
     expect(
       getProperty('age', {
         name: 'Fred',
@@ -70,7 +70,7 @@ describe('hasProperty', () => {
     age: 23
   };
 
-  xit('returns true if the object has the given property', () => {
+  it('returns true if the object has the given property', () => {
     expect(hasProperty('age', fred)).toBe(true);
     expect(hasProperty('name', tom)).toBe(true);
     expect(hasProperty('favouriteColour', fred)).toBe(false);
@@ -79,7 +79,7 @@ describe('hasProperty', () => {
 });
 
 describe('isOver65', () => {
-  xit('returns true if the person is aged over 65', () => {
+  it('returns true if the person is aged over 65', () => {
     const jim = {
       name: 'Jim',
       age: 66
@@ -125,7 +125,7 @@ describe('getAges', () => {
 });
 
 describe('findByName', () => {
-  xit('returns the person with the given name', () => {
+  it('returns the person with the given name', () => {
     const jim = {
       name: 'Jim',
       age: 66
@@ -147,7 +147,7 @@ describe('findByName', () => {
 });
 
 describe('findHondas', () => {
-  xit('returns a list of cars manufactured by Honda', () => {
+  it('returns a list of cars manufactured by Honda', () => {
     const car1 = {
       manufacturer: 'Honda',
       year: 1997,
@@ -179,7 +179,7 @@ describe('findHondas', () => {
 });
 
 describe('averageAge', () => {
-  xit('returns the average age of the people in the list', () => {
+  it('returns the average age of the people in the list', () => {
     const john = {
       name: 'John',
       age: 60
@@ -207,7 +207,7 @@ describe('averageAge', () => {
 });
 
 describe('createTalkingPerson', () => {
-  xit('returns a person who can introduce themselves', () => {
+  it('returns a person who can introduce themselves', () => {
     const bill = createTalkingPerson('Bill', 40);
     const catherine = createTalkingPerson('Catherine', 21);
     expect(bill).toEqual({
diff --git a/src/__tests__/strings.test.js b/src/__tests__/strings.test.js
index e2c3c887..b19fd739 100644
--- a/src/__tests__/strings.test.js
+++ b/src/__tests__/strings.test.js
@@ -8,21 +8,21 @@ const {
 } = require('../strings');
 
 describe('sayHello', () => {
-  xit('returns "Hello world!" when passed "world"', () => {
+  it('returns "Hello world!" when passed "world"', () => {
     expect(sayHello('world')).toEqual('Hello, world!');
   });
 
-  xit('returns "Hello MCR Codes!" when passed "MCR Codes"', () => {
+  it('returns "Hello MCR Codes!" when passed "MCR Codes"', () => {
     expect(sayHello('MCR Codes')).toEqual('Hello, MCR Codes!');
   });
 
-  xit('returns "Hello fsghjdfkhgf!" when passed "fsghjdfkhgf"', () => {
+  it('returns "Hello fsghjdfkhgf!" when passed "fsghjdfkhgf"', () => {
     expect(sayHello('fsghjdfkhgf')).toEqual('Hello, fsghjdfkhgf!');
   });
 });
 
 describe('uppercase', () => {
-  xit('returns the uppercased string', () => {
+  it('returns the uppercased string', () => {
     expect(uppercase('abc')).toEqual('ABC');
     expect(uppercase('def')).toEqual('DEF');
     expect(uppercase('ghi')).toEqual('GHI');
@@ -30,7 +30,7 @@ describe('uppercase', () => {
 });
 
 describe('lowercase', () => {
-  xit('returns the lowercased string', () => {
+  it('returns the lowercased string', () => {
     expect(lowercase('ABC')).toEqual('abc');
     expect(lowercase('DEF')).toEqual('def');
     expect(lowercase('GHI')).toEqual('ghi');
@@ -38,7 +38,7 @@ describe('lowercase', () => {
 });
 
 describe('countCharacters', () => {
-  xit('returns the number of characters in the string', () => {
+  it('returns the number of characters in the string', () => {
     expect(countCharacters('fsfsgsfdg')).toEqual(9);
     expect(countCharacters('fsfsg')).toEqual(5);
     expect(countCharacters('')).toEqual(0);
@@ -46,7 +46,7 @@ describe('countCharacters', () => {
 });
 
 describe('firstCharacter', () => {
-  xit('returns the first character of the string', () => {
+  it('returns the first character of the string', () => {
     expect(firstCharacter('ABC')).toEqual('A');
     expect(firstCharacter('DEF')).toEqual('D');
     expect(firstCharacter('GHI')).toEqual('G');
@@ -54,11 +54,11 @@ describe('firstCharacter', () => {
 });
 
 describe('firstCharacters', () => {
-  xit('returns the first 4 characters of the string', () => {
+  it('returns the first 4 characters of the string', () => {
     expect(firstCharacters('sd32fg45', 4)).toEqual('sd32');
   });
 
-  xit('returns the first 2 characters of the string', () => {
+  it('returns the first 2 characters of the string', () => {
     expect(firstCharacters('asd', 2)).toEqual('as');
   });
 });
diff --git a/src/arrays.js b/src/arrays.js
index 822c49b7..d9591a1b 100644
--- a/src/arrays.js
+++ b/src/arrays.js
@@ -1,5 +1,5 @@
 const getNthElement = (index, array) => {
-  // your code here
+console.log ([index] array);
 };
 
 const arrayToCSVString = array => {
diff --git a/src/booleans.js b/src/booleans.js
index 5ff6cb55..dbf3c3ac 100644
--- a/src/booleans.js
+++ b/src/booleans.js
@@ -1,61 +1,91 @@
 function negate(a) {
-  // your code here
+  return !a
+ 
 };
 
 function both(a, b) {
-  // your code here
+   if (a===true && b===true){
+    return true;
+   } else{
+    return false;
+   }
 };
 
 function either(a, b) {
-  // your code here
+  if (a || b){
+    return true;
+  }else{
+    return false;
+  }
 };
 
 function none(a, b) {
-  // your code here
+  if (a || b){
+    return false;
+  }else{
+    return true;
+  }
 };
 
 function one(a, b) {
-  // your code here
+if (a===true && b===true) {
+  return false;
+}
+if (a!==true && b===true){
+  return true;
+}
+if (a!==true && b!==true){
+  return false;
+}
+if(a===true && b!==true){
+  return true;
+}
+
 };
 
 function truthiness(a) {
-  // your code here
+  if (true){
+    return true;
+  } else {
+    return false;
+  }
 };
 
 function isEqual(a, b) {
-  // your code here
+  return a===b;
 };
 
 function isGreaterThan(a, b) {
-  // your code here
+  return a > b;
 };
 
 function isLessThanOrEqualTo(a, b) {
-  // your code here
+  return a <= b;
 };
 
 function isOdd(a) {
-  // your code here
+  return a % 2 !== 0;
 };
 
 function isEven(a) {
-  // your code here
+  return a % 2 === 0;
 };
 
 function isSquare(a) {
-  // your code here
+ const sqrt = Math.sqrt(a);
+ return sqrt === Math.floor(sqrt);
 };
 
 function startsWith(char, string) {
-  // your code here
+  return string.charAt(0) === char;
 };
 
 function containsVowels(string) {
-  // your code here
+  return /[aeiouAEIOU]/.test(string);
 };
 
 function isLowerCase(string) {
-  // your code here
+  return string === string.toLowerCase();
 };
 
 module.exports = {
diff --git a/src/numbers.js b/src/numbers.js
index d3eab646..32fadc8a 100644
--- a/src/numbers.js
+++ b/src/numbers.js
@@ -1,45 +1,45 @@
 function add (a, b) {
-  // your code here
+  return a + b;
 }
 
 function subtract (a, b) {
-  // your code here
+  return a - b;
 }
 
 function multiply (a, b) {
-  // your code here
+  return a * b;
 }
 
 function divide (a, b) {
-  // your code here
+  return a / b;
 }
 
 function power (a, b) {
-  // your code here
+  return a ** b;
 }
 
 function round (a) {
-  // your code here
+  return Math.round (a);
 }
 
 function roundUp (a) {
-  // your code here
+  return Math.ceil(a)
 }
 
 function roundDown (a) {
-  // your code here
+  return Math.floor(a)
 }
 
 function absolute (a) {
-  // your code here
+  return Math.abs(a)
 }
 
 function quotient (a, b) {
-  // your code here
+  return Math.trunc (a/b);
 }
 
 function remainder (a, b) {
-  // your code here
+  return a%b
 }
 
 module.exports = {
diff --git a/src/objects.js b/src/objects.js
index 906eef8f..1ce8be58 100644
--- a/src/objects.js
+++ b/src/objects.js
@@ -1,41 +1,53 @@
 const createPerson = (name, age) => {
-  // your code here
+  return {
+    name:name,
+    age:age
+  };
 };
 
 const getName = object => {
-  // your code here
+  return object.name;
 };
 
 const getProperty = (property, object) => {
-  // your code here
+  return object[property];
 };
 
 const hasProperty = (property, object) => {
-  // your code here
+  return object.hasOwnProperty(property);
 };
 
 const isOver65 = person => {
-  // your code here
+ return person.age > 65;
 };
 
 const getAges = people => {
-  // your code here
+const ages = [];
 };
 
 const findByName = (name, people) => {
-  // your code here
+ return people.find (people => people.name === name);
 };
 
 const findHondas = cars => {
-  // your code here
+  return cars.filter(cars => cars.manufacturer === 'Honda');
 };
 
 const averageAge = people => {
-  // your code here
+  if (people.length === 0){
+    return 0;
+  };
+  const totalAge = people.reduce((sum,person) => sum + person.age, 0);
+  const average = totalAge / people.length;
+  return average;
 };
 
 const createTalkingPerson = (name, age) => {
-  // your code here
+ return {
+  introduce: function(otherPerson) {
+    return 'Hi' + otherPerson + 'my name is' + name + 'and I am' + age +'!'
+  };
+ };
 };
 
 module.exports = {
diff --git a/src/strings.js b/src/strings.js
index ce02affa..77c1a193 100644
--- a/src/strings.js
+++ b/src/strings.js
@@ -1,25 +1,25 @@
 function sayHello (string) {
-  // your code here
+ return "Hello, " + string + "!";
 };
 
 function uppercase (string) {
-  // your code here
+  return string.toUpperCase();
 };
 
 function lowercase (string) {
-  // your code here
+return string.toLowerCase();
 };
 
 function countCharacters (string) {
-  // your code here
+  return string.length;
 };
 
 function firstCharacter (string) {
-  // your code here
+  return string[0];
 };
 
 function firstCharacters (string, n) {
-  // your code here
+ return string.slice(0,n);
 };
 
 module.exports = {