diff --git a/1-exercises/A-array-find/exercise.js b/1-exercises/A-array-find/exercise.js
index 35902fed..7711bac3 100644
--- a/1-exercises/A-array-find/exercise.js
+++ b/1-exercises/A-array-find/exercise.js
@@ -17,9 +17,10 @@ let names = [
   "Ahmed",
 ];
 
-let longNameThatStartsWithA = findLongNameThatStartsWithA(names);
+let longNameThatStartsWithA = names.find(name => name.startsWith("A") && name.length > 7);
+console.log(longNameThatStartsWithA); 
+
 
-console.log(longNameThatStartsWithA);
 
 /* EXPECTED OUTPUT */
 // "Alexandra"
diff --git a/1-exercises/B-array-some/exercise.js b/1-exercises/B-array-some/exercise.js
index fddc69ee..48225163 100644
--- a/1-exercises/B-array-some/exercise.js
+++ b/1-exercises/B-array-some/exercise.js
@@ -15,6 +15,14 @@ let pairsByIndex = [[0, 3], [1, 2], [2, 1], null, [3, 0]];
 let students = ["Islam", "Lesley", "Harun", "Rukmini"];
 let mentors = ["Daniel", "Irina", "Mozafar", "Luke"];
 
+function isNull(pair){
+  return pair === null;
+ }
+
+if(pairsByIndex.some(isNull)){
+    process.exit(1);
+}
+
 let pairs = pairsByIndex.map(function (indexes) {
   let student = students[indexes[0]];
   let mentor = mentors[indexes[1]];
diff --git a/1-exercises/C-array-every/exercise.js b/1-exercises/C-array-every/exercise.js
index 347b9632..128f04fc 100644
--- a/1-exercises/C-array-every/exercise.js
+++ b/1-exercises/C-array-every/exercise.js
@@ -5,9 +5,8 @@
 let students = ["Omar", "Austine", "Dany", "Swathi", "Lesley", "Rukmini"];
 let group = ["Austine", "Dany", "Swathi", "Daniel"];
 
-let groupIsOnlyStudents; // complete this statement
-
-if (groupIsOnlyStudents) {
+let groupIsOnlyStudents = group.every(student => students.includes(student)); // complete this statement
+if(groupIsOnlyStudents){
   console.log("The group contains only students");
 } else {
   console.log("The group does not contain only students");
diff --git a/1-exercises/D-array-filter/exercise.js b/1-exercises/D-array-filter/exercise.js
index 51837028..a3bcd292 100644
--- a/1-exercises/D-array-filter/exercise.js
+++ b/1-exercises/D-array-filter/exercise.js
@@ -8,11 +8,17 @@
 
 let pairsByIndexRaw = [[0, 3], [1, 2], [2, 1], null, [1], false, "whoops"];
 
-let pairsByIndex; // Complete this statement
 
 let students = ["Islam", "Lesley", "Harun", "Rukmini"];
 let mentors = ["Daniel", "Irina", "Mozafar", "Luke"];
 
+let pairsByIndex = pairsByIndexRaw.filter(function(pair){
+  return Array.isArray(pair) && pair.length === 2 && typeof pair[0] === "number" && typeof pair[1] === "number" && pair[0] < students.length && pair[1] < mentors.length;
+}); // Complete this statement
+
+// let students = ["Islam", "Lesley", "Harun", "Rukmini"];
+// let mentors = ["Daniel", "Irina", "Mozafar", "Luke"];
+
 let pairs = pairsByIndex.map(function (indexes) {
   let student = students[indexes[0]];
   let mentor = mentors[indexes[1]];
diff --git a/1-exercises/E-array-map/exercise.js b/1-exercises/E-array-map/exercise.js
index 5a157279..5810761a 100644
--- a/1-exercises/E-array-map/exercise.js
+++ b/1-exercises/E-array-map/exercise.js
@@ -3,7 +3,9 @@
 
 let numbers = [0.1, 0.2, 0.3, 0.4, 0.5];
 
-let numbersMultipliedByOneHundred; // complete this statement
+let numbersMultipliedByOneHundred = numbers.map(function(numbersMultipliedByOneHundred){
+  return numbersMultipliedByOneHundred * 100;
+}); // complete this statement
 
 console.log(numbersMultipliedByOneHundred);
 
diff --git a/1-exercises/F-array-forEach/exercise.js b/1-exercises/F-array-forEach/exercise.js
index 985068cc..ad538bf7 100644
--- a/1-exercises/F-array-forEach/exercise.js
+++ b/1-exercises/F-array-forEach/exercise.js
@@ -9,6 +9,18 @@
 
 let arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
 
+arr.forEach(num => {
+  if (num % 3 === 0){
+    console.log("Fizz");
+  } else if(num % 5 === 0){
+    console.log("Buzz");
+  }else if(num % 3 === 0 && num % 5 === 0) {
+    console.log("Fizzbuzz");
+  } else{
+    console.log(num);
+  }
+});
+
 /* EXPECTED OUTPUT */
 
 /*
diff --git a/1-exercises/G-array-methods/exercise.js b/1-exercises/G-array-methods/exercise.js
index 4367ef6e..bc504f2a 100644
--- a/1-exercises/G-array-methods/exercise.js
+++ b/1-exercises/G-array-methods/exercise.js
@@ -4,7 +4,7 @@
 */
 
 let numbers = [3, 2, 1];
-let sortedNumbers; // complete this statement
+let sortedNumbers = numbers.sort(); // complete this statement
 
 /* 
   DO NOT EDIT BELOW THIS LINE
diff --git a/1-exercises/H-array-methods-2/exercise.js b/1-exercises/H-array-methods-2/exercise.js
index 59c5daa7..25322276 100644
--- a/1-exercises/H-array-methods-2/exercise.js
+++ b/1-exercises/H-array-methods-2/exercise.js
@@ -15,8 +15,8 @@ let everyone = [
   "Swathi",
 ];
 
-let firstFive; // complete this statement
-let lastFive; // complete this statement
+let firstFive = everyone.slice(0, 5); // complete this statement
+let lastFive = everyone.slice(2, 6); // complete this statement
 
 /* 
   DO NOT EDIT BELOW THIS LINE
diff --git a/1-exercises/H-array-methods-2/exercise2.js b/1-exercises/H-array-methods-2/exercise2.js
index 14bb4318..dd796568 100644
--- a/1-exercises/H-array-methods-2/exercise2.js
+++ b/1-exercises/H-array-methods-2/exercise2.js
@@ -7,12 +7,30 @@
   Tip: use the string method .split() and the array method .join()
 */
 
-function capitalise(str) {}
+function capitalise(str) {
+  // return str.charAt(0).toUpperCase() + str.slice(1);
+  const chars = str.split("");
+  console.log(chars[0].join(""));
+}
+
+function capitalise(str) {
+  // split the string into an array of words
+  const words = str.split(" ");
+
+  // iterate over each word and capitalise the first letter
+  const capitalisedWords = words.map((word) => {
+    return word.charAt(0).toUpperCase() + word.slice(1);
+  });
+
+  // join the capitalised words back into a string and return it
+  return capitalisedWords.join(" ");
+}
+
 
 /* 
   DO NOT EDIT BELOW THIS LINE
   --------------------------- */
-let name = "daniel";
+const name = "daniel";
 
 console.log(capitalise(name));
 console.log(capitalise("hello"));
diff --git a/1-exercises/H-array-methods-2/exercise3.js b/1-exercises/H-array-methods-2/exercise3.js
index c8e079e4..b3973fb0 100644
--- a/1-exercises/H-array-methods-2/exercise3.js
+++ b/1-exercises/H-array-methods-2/exercise3.js
@@ -7,8 +7,15 @@
 let ukNations = ["Scotland", "Wales", "England", "Northern Ireland"];
 
 function isInUK(country) {
-  return; // complete this statement
+  for (let ukNation of ukNations){
+   const isInUK = ukNations.includes(country);
+   return isInUK;
+  }; // complete this statement
 }
+const isFrance = isInUK("France");
+const isRepublicOfIreland = isInUK("Republic of Ireland");
+const isEngland = isInUK("England");
+
 
 /* 
   DO NOT EDIT BELOW THIS LINE
diff --git a/1-exercises/I-string-replace/exercise.js b/1-exercises/I-string-replace/exercise.js
index 3f7104d7..64b8d63f 100644
--- a/1-exercises/I-string-replace/exercise.js
+++ b/1-exercises/I-string-replace/exercise.js
@@ -13,7 +13,10 @@
 let story =
   "I like dogs. One day I went to the park and I saw 10 dogs. It was a great day.";
 
-let result = story.replace("", "");
+// let result = story.replace("dogs", "cats").replace("day", "night").replace("10", "100000").replace("great", "brilliant"); why not correct
+
+let result = story.replace(/dogs/g, "cats").replace(/day/g, "night").replace(/10/g, "100000").replace(/great/g, "brilliant");
+
 
 /* EXPECTED OUTPUT */
 
diff --git a/2-mandatory/1-create-functions.js b/2-mandatory/1-create-functions.js
index 6df12961..ecd550a9 100644
--- a/2-mandatory/1-create-functions.js
+++ b/2-mandatory/1-create-functions.js
@@ -3,7 +3,8 @@ Write a function that:
 - Accepts an array as a parameter.
 - Returns a new array containing the first five elements of the passed array.
 */
-function first5() {
+function first5(array) {
+  return array.slice(0, 5);
 }
 
 /*
@@ -11,7 +12,8 @@ Write a function that:
 - Accepts an array as a parameter.
 - Returns a new array containing the same elements, except sorted.
 */
-function sortArray() {
+function sortArray(array) {
+  return array.some();
 }
 
 /*
diff --git a/2-mandatory/2-oxygen-levels.js b/2-mandatory/2-oxygen-levels.js
index 5711c5e5..dca8ef5b 100644
--- a/2-mandatory/2-oxygen-levels.js
+++ b/2-mandatory/2-oxygen-levels.js
@@ -10,8 +10,12 @@
 
     Some string methods that might help you here are .replace() and .substring().
 */
-
-function findSafeOxygenLevel() {}
+function isSafeOxygenLevel(oxygenLevel){
+  return parseFloat(oxygenLevel)>19.5 && parseFloat(oxygenLevel)<23.5;
+}
+function findSafeOxygenLevel(oxygenLevels) {
+  return oxygenLevels.find(isSafeOxygenLevel);
+}
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
diff --git a/2-mandatory/3-bush-berries.js b/2-mandatory/3-bush-berries.js
index b434a507..8b77cc54 100644
--- a/2-mandatory/3-bush-berries.js
+++ b/2-mandatory/3-bush-berries.js
@@ -1,3 +1,4 @@
+
 /*
   The space travellers have safely landed and are foraging for food in the natural wildlife.
 
@@ -25,6 +26,12 @@ function isBushSafe(berryArray) {
   //Write your code here
 }
 
+/*if (isVegetarian) {
+  return "Macaroni and Cheese";
+} else {
+  return "Steak and Chips";
+}*/
+
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 test("isBushSafe finds toxic busy", () => {
diff --git a/3-extra/1-card-vailidator.md b/3-extra/1-card-vailidator.md
index 65ace5bc..786b9eb0 100644
--- a/3-extra/1-card-vailidator.md
+++ b/3-extra/1-card-vailidator.md
@@ -34,3 +34,4 @@ These are the requirements your project needs to fulfill:
 - Use `node` from the command line to test if your code works as expected.
 
 Good luck!
+