diff --git a/src/__tests__/arrays.test.js b/src/__tests__/arrays.test.js
index d00a5566..319dd620 100644
--- a/src/__tests__/arrays.test.js
+++ b/src/__tests__/arrays.test.js
@@ -19,34 +19,34 @@ 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');
   });
 
-  xit('if n is greater than the number of elements, it cycles back to the start', () => {
+  it('if n is greater than the number of elements, it cycles back to the start', () => {
     expect(getNthElement(4, array)).toEqual('cat');
     expect(getNthElement(5, array)).toEqual('dog');
   });
 });
 
 describe('arrayToCSVString', () => {
-  xit('returns the array elements as a comma-seperated string', () => {
+  it('returns the array elements as a comma-seperated string', () => {
     expect(arrayToCSVString(['a', 'b', 'c', 'd'])).toEqual('a,b,c,d');
     expect(arrayToCSVString([1, 2, 3, 4, 5])).toEqual('1,2,3,4,5');
   });
 });
 
 describe('csvStringToArray', () => {
-  xit('converts the csv string as an array', () => {
+  it('converts the csv string as an array', () => {
     expect(csvStringToArray('a,b,c,d')).toEqual(['a', 'b', 'c', 'd']);
     expect(csvStringToArray('1,2,3,4,5')).toEqual(['1', '2', '3', '4', '5']);
   });
 });
 
 describe('addToArray', () => {
-  xit('adds the item to the end of the array', () => {
+  it('adds the item to the end of the array', () => {
     const array = [];
     const array2 = [1, 2, 3];
 
@@ -59,7 +59,7 @@ describe('addToArray', () => {
 });
 
 describe('addToArray2', () => {
-  xit('returns a new array with the value appended', () => {
+  it('returns a new array with the value appended', () => {
     const array = ['a', 'b', 'c'];
     const array2 = [1, 2, 3];
 
@@ -72,7 +72,7 @@ describe('addToArray2', () => {
 });
 
 describe('removeNthElement', () => {
-  xit('removes the element at position n', () => {
+  it('removes the element at position n', () => {
     const array = ['ant', 'bison', 'cockerel', 'duck', 'elephant'];
     removeNthElement(2, array);
     expect(array).toEqual(['ant', 'bison', 'duck', 'elephant']);
@@ -84,14 +84,14 @@ describe('removeNthElement', () => {
 });
 
 describe('numbersToStrings', () => {
-  xit('converts every number in the array to a string', () => {
+  it('converts every number in the array to a string', () => {
     expect(numbersToStrings([1, 2, 3])).toEqual(['1', '2', '3']);
     expect(numbersToStrings([7, 8, 9])).toEqual(['7', '8', '9']);
   });
 });
 
 describe('uppercaseWordsInArray', () => {
-  xit('makes every string in the array uppercase', () => {
+  it('makes every string in the array uppercase', () => {
     expect(uppercaseWordsInArray(['cat', 'mouse', 'banana'])).toEqual([
       'CAT',
       'MOUSE',
@@ -106,7 +106,7 @@ describe('uppercaseWordsInArray', () => {
 });
 
 describe('reverseWordsInArray', () => {
-  xit('reverses every string in an array', () => {
+  it('reverses every string in an array', () => {
     expect(reverseWordsInArray(['cat', 'Mouse', 'banana'])).toEqual([
       'tac',
       'esuoM',
@@ -121,14 +121,14 @@ describe('reverseWordsInArray', () => {
 });
 
 describe('onlyEven', () => {
-  xit('filters the array and only returns even numbers', () => {
+  it('filters the array and only returns even numbers', () => {
     expect(onlyEven([1, 2, 3, 4, 5, 6, 7, 8])).toEqual([2, 4, 6, 8]);
     expect(onlyEven([8, 9, 10, 11, 12, 13, 14, 15])).toEqual([8, 10, 12, 14]);
   });
 });
 
 describe('removeNthElement2', () => {
-  xit('returns an array with the nth element removed, and does not mutate the original', () => {
+  it('returns an array with the nth element removed, and does not mutate the original', () => {
     const array = ['bike', 'car', 'train', 'bus'];
     expect(removeNthElement2(2, array)).toEqual(['bike', 'car', 'bus']);
     expect(array).toEqual(['bike', 'car', 'train', 'bus']);
@@ -139,7 +139,7 @@ describe('removeNthElement2', () => {
 });
 
 describe('elementsStartingWithAVowel', () => {
-  xit('returns elements starting with a vowel', () => {
+  it('returns elements starting with a vowel', () => {
     expect(
       elementsStartingWithAVowel([
         'apple',
@@ -179,7 +179,7 @@ describe('elementsStartingWithAVowel', () => {
     ).toEqual(['aaaa', 'eeee']);
   });
 
-  xit('is case insensitive', () => {
+  it('is case insensitive', () => {
     expect(
       elementsStartingWithAVowel([
         'Apple',
@@ -221,7 +221,7 @@ describe('elementsStartingWithAVowel', () => {
 });
 
 describe('removeSpaces', () => {
-  xit('returns the string with the space characters removed', () => {
+  it('returns the string with the space characters removed', () => {
     expect(removeSpaces('this string has spaces')).toEqual(
       'thisstringhasspaces'
     );
@@ -232,14 +232,14 @@ describe('removeSpaces', () => {
 });
 
 describe('sumNumbers', () => {
-  xit('returns the sum of the numbers in the array', () => {
+  it('returns the sum of the numbers in the array', () => {
     expect(sumNumbers([1, 3, 5, 6, 2, 8])).toEqual(25);
     expect(sumNumbers([1, 3, 5])).toEqual(9);
   });
 });
 
 describe('sortByLastLetter', () => {
-  xit('sorts the string by the last character', () => {
+  it('sorts the string by the last character', () => {
     expect(
       sortByLastLetter(['Lannister', 'Stark', 'Greyjoy', 'Targaryen'])
     ).toEqual(['Stark', 'Targaryen', 'Lannister', 'Greyjoy']);
diff --git a/src/__tests__/booleans.test.js b/src/__tests__/booleans.test.js
index 734201d5..062a01de 100644
--- a/src/__tests__/booleans.test.js
+++ b/src/__tests__/booleans.test.js
@@ -17,14 +17,14 @@ 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);
@@ -33,7 +33,7 @@ describe('both', () => {
 });
 
 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);
@@ -60,7 +60,7 @@ describe('one', () => {
 });
 
 describe('truthiness', () => {
-  xit('returns the truthiness of the given value', () => {
+  it('returns the truthiness of the given value', () => {
     expect(truthiness('')).toBe(false);
     expect(truthiness('dbbd')).toBe(true);
     expect(truthiness(0)).toBe(false);
@@ -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);
@@ -146,15 +146,23 @@ 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('cAt')).toBe(true);
+    expect(containsVowels('cet')).toBe(true);
+    expect(containsVowels('cEt')).toBe(true);
+    expect(containsVowels('cit')).toBe(true);
+    expect(containsVowels('cIt')).toBe(true);
     expect(containsVowels('DOG')).toBe(true);
+    expect(containsVowels('DoG')).toBe(true);
+    expect(containsVowels('DUG')).toBe(true);
+    expect(containsVowels('DuG')).toBe(true);
     expect(containsVowels('why')).toBe(false);
   });
 });
 
 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..1755397f 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
@@ -102,7 +102,7 @@ describe('isOver65', () => {
 });
 
 describe('getAges', () => {
-  xit('returns the ages of each person in the array', () => {
+  it('returns the ages of each person in the array', () => {
     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..bdbe6000 100644
--- a/src/arrays.js
+++ b/src/arrays.js
@@ -1,61 +1,64 @@
 const getNthElement = (index, array) => {
-  // your code here
+  if (index >=array.length) {
+    return array [index-array.length]
+  }
+  return array[index];
 };
 
-const arrayToCSVString = array => {
-  // your code here
+const arrayToCSVString = array => {;
+  return array.join(",");
 };
 
 const csvStringToArray = string => {
-  // your code here
+  return string.split(",");
 };
 
 const addToArray = (element, array) => {
-  // your code here
+  array.push(element);
 };
 
 const addToArray2 = (element, array) => {
-  // your code here
+  return array.concat(element);
 };
 
 const removeNthElement = (index, array) => {
-  // your code here
+  array.splice (index,1);
 };
 
 const numbersToStrings = numbers => {
-  // your code here
+  return numbers.map(String);
 };
 
 const uppercaseWordsInArray = strings => {
-  // your code here
+    return strings.map(element => element.toUpperCase());
 };
 
 const reverseWordsInArray = strings => {
-  // your code here
+  return strings.map(strings => strings.split("").reverse().join(""));
 };
 
 const onlyEven = numbers => {
-  // your code here
+  return numbers.filter(numbers => numbers % 2 === 0);
 };
 
 const removeNthElement2 = (index, array) => {
-  // your code here
+  return array.filter((_,itemindex) => itemindex !== index)
 };
 
 const elementsStartingWithAVowel = strings => {
-  // your code here
+  return strings.filter(strings => /^[aeiou]/i.test(strings));
 };
 
 const removeSpaces = string => {
-  // your code here
+  return string.replace(/\s/g, '');
 };
 
 const sumNumbers = numbers => {
-  // your code here
+  return numbers.reduce((total, item) => total + item);
 };
 
 const sortByLastLetter = strings => {
-  // your code here
+  return strings.sort((a,b) => a.charCodeAt(a.length-1) - b.charCodeAt(b.length-1));
 };
 
 module.exports = {
diff --git a/src/booleans.js b/src/booleans.js
index 5ff6cb55..cd3af561 100644
--- a/src/booleans.js
+++ b/src/booleans.js
@@ -1,61 +1,79 @@
 function negate(a) {
-  // your code here
+  return !a;
 };
 
 function both(a, b) {
-  // your code here
+  return a && b;
 };
 
 function either(a, b) {
-  // your code here
+  return a || b;
 };
 
 function none(a, b) {
-  // your code here
-};
+  return !a && !b;
+}
 
 function one(a, b) {
-  // your code here
+  return (a || b) && !(a && b);
 };
 
 function truthiness(a) {
-  // your code here
-};
+  if (a) {
+    return true;
+  }
+  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 Math.abs(a % 2) === 1;
 };
 
 function isEven(a) {
-  // your code here
+  if (a % 2 === 0) {
+    return true;
+  } else {
+    return false;
+  }
 };
 
 function isSquare(a) {
-  // your code here
+  return Math.sqrt(a) === Math.round(Math.sqrt(a));
 };
 
 function startsWith(char, string) {
-  // your code here
+  return string.charAt(0) === char;
 };
 
+// function containsVowels(string) {
+//   string = string.toLowerCase();
+//   return string.indexOf("a") > -1
+//     || string.indexOf("e") > -1 
+//     || string.indexOf("i") > -1 
+//     || string.indexOf("o") > -1 
+//     || string.indexOf("u") > -1
+// }
 function containsVowels(string) {
-  // your code here
-};
-
+  return /[aeiou]/i.test(string);
+}
+// function isLowerCase(string) {
+//   const lowercasedString = string.toLowerCase();
+//   return lowercasedString === string
+// };
 function isLowerCase(string) {
-  // your code here
+  return !/[A-Z]/.test(string)
 };
 
 module.exports = {
diff --git a/src/numbers.js b/src/numbers.js
index d3eab646..61302a87 100644
--- a/src/numbers.js
+++ b/src/numbers.js
@@ -1,45 +1,47 @@
 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
+  const divided = (a/b);
+  const quotient = Math.trunc(divided);
+  return quotient;
 }
 
 function remainder (a, b) {
-  // your code here
+  return a % b;
 }
 
 module.exports = {
diff --git a/src/objects.js b/src/objects.js
index 906eef8f..c4c0edb0 100644
--- a/src/objects.js
+++ b/src/objects.js
@@ -1,41 +1,56 @@
 const createPerson = (name, age) => {
-  // your code here
+  return {
+    name: name, 
+    age: age
+  }
 };
 
-const getName = object => {
-  // your code here
-};
+function getName(object) {
+  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
+  return people.map(person => {
+    return person.age;
+  });
 };
 
 const findByName = (name, people) => {
-  // your code here
+  return people.find(person => person.name === name);
 };
 
 const findHondas = cars => {
-  // your code here
+  return cars.filter(car => {
+    return car.manufacturer === 'Honda';
+  });
 };
 
 const averageAge = people => {
-  // your code here
-};
+  const totalAge = people.reduce((previousAge, currentPerson) => {
+    return previousAge + currentPerson.age;}, 0);
+return totalAge / people.length;
+  };
 
 const createTalkingPerson = (name, age) => {
-  // your code here
+  return {
+    name, 
+    age,
+    introduce(strangerName) {
+      return `Hi ${strangerName}, my name is ${this.name} and I am ${this.age}!`;
+    }
+  };
 };
 
 module.exports = {
diff --git a/src/strings.js b/src/strings.js
index ce02affa..da4394bc 100644
--- a/src/strings.js
+++ b/src/strings.js
@@ -1,26 +1,30 @@
-function sayHello (string) {
-  // your code here
-};
-
+function sayHello(string) {
+  const response = "Hello, " + string + "!";
+  return response;
+  // return "Hello, " + string + "!";
+  // return "Hello, ".concat(string).concat("!");
+}
 function uppercase (string) {
-  // your code here
+  let result = string.toLocaleUpperCase();
+  return result;
 };
 
 function lowercase (string) {
-  // your code here
+  let result = string.toLocaleLowerCase();
+  return result;
 };
 
 function countCharacters (string) {
-  // your code here
+  return string.length;
 };
 
 function firstCharacter (string) {
-  // your code here
+  return string.charAt(0);
 };
 
 function firstCharacters (string, n) {
-  // your code here
-};
+  return string.substring(0, n);
+}
 
 module.exports = {
   sayHello,