diff --git a/Sprint-3/1-key-implement/1-get-angle-type.js b/Sprint-3/1-key-implement/1-get-angle-type.js
index 08d1f0cba..8aa87c605 100644
--- a/Sprint-3/1-key-implement/1-get-angle-type.js
+++ b/Sprint-3/1-key-implement/1-get-angle-type.js
@@ -9,6 +9,10 @@
 
 function getAngleType(angle) {
    if (angle === 90) return "Right angle";
+   else if (angle === 45) return "Acute angle";
+   else if (angle > 90 && angle < 180) return "obtuse angle";
+   else if (angle === 180) return "Straight angle";
+   else if (angle > 180 && angle < 360) return "Reflex angle";
    // read to the end, complete line 36, then pass your test here
 }
 
@@ -43,14 +47,18 @@ assertEquals(acute, "Acute angle");
 // When the angle is greater than 90 degrees and less than 180 degrees,
 // Then the function should return "Obtuse angle"
 const obtuse = getAngleType(120);
-// ====> write your test here, and then add a line to pass the test in the function above
+assertEquals(obtuse, "obtuse angle");
 
 // Case 4: Identify Straight Angles:
 // When the angle is exactly 180 degrees,
 // Then the function should return "Straight angle"
 // ====> write your test here, and then add a line to pass the test in the function above
+const straight = getAngleType(180);
+assertEquals(straight, "Straight angle");
 
 // Case 5: Identify Reflex Angles:
 // When the angle is greater than 180 degrees and less than 360 degrees,
 // Then the function should return "Reflex angle"
-// ====> write your test here, and then add a line to pass the test in the function above
\ No newline at end of file
+// ====> write your test here, and then add a line to pass the test in the function above
+const reflex = getAngleType(240);
+assertEquals(reflex, "Reflex angle");
diff --git a/Sprint-3/1-key-implement/2-is-proper-fraction.js b/Sprint-3/1-key-implement/2-is-proper-fraction.js
index 91583e941..10bc0938e 100644
--- a/Sprint-3/1-key-implement/2-is-proper-fraction.js
+++ b/Sprint-3/1-key-implement/2-is-proper-fraction.js
@@ -8,7 +8,9 @@
 // write one test at a time, and make it pass, build your solution up methodically
 
 function isProperFraction(numerator, denominator) {
-    if (numerator < denominator) return true;
+    if (denominator === 0) return "Undefined";
+    else if (numerator < denominator) return true;
+    else return false;
 }
 
 // here's our helper again
@@ -40,14 +42,23 @@ assertEquals(improperFraction, false);
 // target output: true
 // Explanation: The fraction -4/7 is a proper fraction because the absolute value of the numerator (4) is less than the denominator (7). The function should return true.
 const negativeFraction = isProperFraction(-4, 7);
-// ====> complete with your assertion
+assertEquals(negativeFraction, true);
 
 // Equal Numerator and Denominator check:
 // Input: numerator = 3, denominator = 3
 // target output: false
 // Explanation: The fraction 3/3 is not a proper fraction because the numerator is equal to the denominator. The function should return false.
 const equalFraction = isProperFraction(3, 3);
-// ====> complete with your assertion
+assertEquals(equalFraction, false);
 
 // Stretch:
 // What other scenarios could you test for?
+
+// Not a valid fraction check:
+// Input: numerator = 3, denominator = 0
+// target output: Undefined
+// Explanation: The fraction 3/0 is not a fraction type like proper or improper because division by zero is not allowed in mathematics. The function should return undefined.
+const zeroFraction = isProperFraction(3,0);
+assertEquals(zeroFraction, "Undefined");
+
+
diff --git a/Sprint-3/1-key-implement/3-get-card-value.js b/Sprint-3/1-key-implement/3-get-card-value.js
index aa1cc9f90..717bb14dd 100644
--- a/Sprint-3/1-key-implement/3-get-card-value.js
+++ b/Sprint-3/1-key-implement/3-get-card-value.js
@@ -8,7 +8,12 @@
 // write one test at a time, and make it pass, build your solution up methodically
 // just make one change at a time -- don't rush -- programmers are deep and careful thinkers
 function getCardValue(card) {
-    if (rank === "A") return 11;
+    let rank = card.slice(0, -1);
+    if (rank === "A" || rank === "Ace") return 11;
+    else if (rank >= 2 && rank <= 9) return Number(rank);
+    else if (rank === 10 || rank === "J" || rank === "Q" || rank === "K") return 10;
+    else return "Invalid card rank."
+
 }
 
 // You need to write assertions for your function to check it works in different cases
@@ -25,27 +30,34 @@ function assertEquals(actualOutput, targetOutput) {
 // Given a card string in the format "A♠" (representing a card in blackjack - the last character will always be an emoji for a suit, and all characters before will be a number 2-10, or one letter of J, Q, K, A),
 // When the function getCardValue is called with this card string as input,
 // Then it should return the numerical card value
-const aceofSpades = getCardValue("A♠");
-assertEquals(aceofSpades, 11);
+// const aceofSpades = getCardValue("A♠");
+// assertEquals(aceofSpades, 11);
 
 // Handle Number Cards (2-10):
 // Given a card with a rank between "2" and "9",
 // When the function is called with such a card,
 // Then it should return the numeric value corresponding to the rank (e.g., "5" should return 5).
 const fiveofHearts = getCardValue("5♥");
-// ====> write your test here, and then add a line to pass the test in the function above
+assertEquals(fiveofHearts, 5);
 
 // Handle Face Cards (J, Q, K):
 // Given a card with a rank of "10," "J," "Q," or "K",
 // When the function is called with such a card,
 // Then it should return the value 10, as these cards are worth 10 points each in blackjack.
+const faceCards = getCardValue("J♣");
+assertEquals(faceCards, 10);
 
 // Handle Ace (A):
 // Given a card with a rank of "A",
 // When the function is called with an Ace,
 // Then it should, by default, assume the Ace is worth 11 points, which is a common rule in blackjack.
+const aceCard = getCardValue("Ace♦");
+assertEquals(aceCard, 11);
+
 
 // Handle Invalid Cards:
 // Given a card with an invalid rank (neither a number nor a recognized face card),
 // When the function is called with such a card,
 // Then it should throw an error indicating "Invalid card rank."
+let invalidCrd = getCardValue("12♠");
+assertEquals(invalidCrd, "Invalid card rank.");
diff --git a/Sprint-3/2-mandatory-rewrite/1-get-angle-type.js b/Sprint-3/2-mandatory-rewrite/1-get-angle-type.js
index d61254bd7..a689d3714 100644
--- a/Sprint-3/2-mandatory-rewrite/1-get-angle-type.js
+++ b/Sprint-3/2-mandatory-rewrite/1-get-angle-type.js
@@ -1,5 +1,9 @@
 function getAngleType(angle) {
   if (angle === 90) return "Right angle";
+  else if (angle === 45) return "Acute angle";
+  else if (angle > 90 && angle < 180) return "Obtuse angle";
+  else if (angle === 180) return "Straight angle";
+  else if (angle > 180 && angle < 360) return "Reflex angle";
   // replace with your completed function from key-implement
 
 }
diff --git a/Sprint-3/2-mandatory-rewrite/1-get-angle-type.test.js b/Sprint-3/2-mandatory-rewrite/1-get-angle-type.test.js
index b62827b7c..3978d6921 100644
--- a/Sprint-3/2-mandatory-rewrite/1-get-angle-type.test.js
+++ b/Sprint-3/2-mandatory-rewrite/1-get-angle-type.test.js
@@ -4,21 +4,19 @@ test("should identify right angle (90°)", () => {
   expect(getAngleType(90)).toEqual("Right angle");
 });
 
-// REPLACE the comments with the tests
-// make your test descriptions as clear and readable as possible
 
-// Case 2: Identify Acute Angles:
-// When the angle is less than 90 degrees,
-// Then the function should return "Acute angle"
+test("should identify acute angle (<90°)", () => {
+  expect(getAngleType(45)).toEqual("Acute angle");
+})
 
-// Case 3: Identify Obtuse Angles:
-// When the angle is greater than 90 degrees and less than 180 degrees,
-// Then the function should return "Obtuse angle"
+test("should identify obtuse angle (90° < angle < 180°)", () => {
+  expect(getAngleType(120)).toEqual("Obtuse angle");
+})
 
-// Case 4: Identify Straight Angles:
-// When the angle is exactly 180 degrees,
-// Then the function should return "Straight angle"
+test("should identify straight angle (angle = 180°)", () => {
+  expect(getAngleType(180)).toEqual("Straight angle");
+})
 
-// Case 5: Identify Reflex Angles:
-// When the angle is greater than 180 degrees and less than 360 degrees,
-// Then the function should return "Reflex angle"
+test("should identify reflex angle (180° < angle < 360°)", () => {
+  expect(getAngleType(250)).toEqual("Reflex angle");
+})
diff --git a/Sprint-3/2-mandatory-rewrite/2-is-proper-fraction.js b/Sprint-3/2-mandatory-rewrite/2-is-proper-fraction.js
index 9836fe398..3cad20da1 100644
--- a/Sprint-3/2-mandatory-rewrite/2-is-proper-fraction.js
+++ b/Sprint-3/2-mandatory-rewrite/2-is-proper-fraction.js
@@ -1,6 +1,7 @@
 function isProperFraction(numerator, denominator) {
     if (numerator < denominator) return true;
-    // add your completed function from key-implement here
+    else if (numerator < denominator) return true;
+    else return false;
 }
 
 module.exports = isProperFraction;
\ No newline at end of file
diff --git a/Sprint-3/2-mandatory-rewrite/2-is-proper-fraction.test.js b/Sprint-3/2-mandatory-rewrite/2-is-proper-fraction.test.js
index ff1cc8173..dc173e5ed 100644
--- a/Sprint-3/2-mandatory-rewrite/2-is-proper-fraction.test.js
+++ b/Sprint-3/2-mandatory-rewrite/2-is-proper-fraction.test.js
@@ -5,7 +5,15 @@ test("should return true for a proper fraction", () => {
 });
 
 // Case 2: Identify Improper Fractions:
-
+test("should return false for a improper fraction", () => {
+  expect(isProperFraction(5, 3)).toEqual(false);
+});
 // Case 3: Identify Negative Fractions:
+test("should return false for a improper fraction", () => {
+  expect(isProperFraction(-5, 10)).toEqual(true);
+});
 
 // Case 4: Identify Equal Numerator and Denominator:
+test("should return false for a improper fraction", () => {
+  expect(isProperFraction(10, 10)).toEqual(false);
+});
\ No newline at end of file
diff --git a/Sprint-3/2-mandatory-rewrite/3-get-card-value.js b/Sprint-3/2-mandatory-rewrite/3-get-card-value.js
index 0d95d3736..b07337aed 100644
--- a/Sprint-3/2-mandatory-rewrite/3-get-card-value.js
+++ b/Sprint-3/2-mandatory-rewrite/3-get-card-value.js
@@ -1,5 +1,8 @@
 function getCardValue(card) {
-    // replace with your code from key-implement
-    return 11;
+    let rank = card.slice(0, -1);
+    if (rank === "A" || rank === "Ace") return 11;
+    else if (rank >= 2 && rank <= 9) return Number(rank);
+    else if (rank === 10 || rank === "J" || rank === "Q" || rank === "K") return 10;
+    else return "Invalid card rank."
 }
 module.exports = getCardValue;
\ No newline at end of file
diff --git a/Sprint-3/2-mandatory-rewrite/3-get-card-value.test.js b/Sprint-3/2-mandatory-rewrite/3-get-card-value.test.js
index 03a8e2f34..61b2bbe99 100644
--- a/Sprint-3/2-mandatory-rewrite/3-get-card-value.test.js
+++ b/Sprint-3/2-mandatory-rewrite/3-get-card-value.test.js
@@ -6,6 +6,22 @@ test("should return 11 for Ace of Spades", () => {
     });
 
 // Case 2: Handle Number Cards (2-10):
+test("should return numeric value corresponding to the rank", () => {
+    const fiveofHearts = getCardValue("5♥"); 
+    expect(fiveofHearts).toEqual(5);
+})
 // Case 3: Handle Face Cards (J, Q, K):
+test("should return 10 for J, Q, K, as these cards are worth 10 points each in blackjack.", () => {
+    const faceCards = getCardValue("J♠")
+    expect(faceCards).toEqual(10);
+})
 // Case 4: Handle Ace (A):
+test("should return 11 as Ace as worth 11 points", () => {
+    const aceCard = getCardValue("Ace♦")
+    expect(aceCard).toEqual(11);
+})
 // Case 5: Handle Invalid Cards:
+test("should return invalid card rank, if the number is unrecognized", () => {
+    const invalidCrd = getCardValue("12♠")
+    expect(invalidCrd).toEqual("Invalid card rank.");
+})
diff --git a/Sprint-3/3-mandatory-practice/implement/count.js b/Sprint-3/3-mandatory-practice/implement/count.js
index fce249650..ba7e16554 100644
--- a/Sprint-3/3-mandatory-practice/implement/count.js
+++ b/Sprint-3/3-mandatory-practice/implement/count.js
@@ -1,5 +1,17 @@
 function countChar(stringOfCharacters, findCharacter) {
-    return 5
+    let charNum = stringOfCharacters.split(findCharacter).length -1;
+    return charNum
+
 }
 
-module.exports = countChar;
\ No newline at end of file
+
+module.exports = countChar;
+
+
+/* pseudocode:
+    // we need to look for a specific character inside a string
+
+
+
+
+*/
diff --git a/Sprint-3/3-mandatory-practice/implement/count.test.js b/Sprint-3/3-mandatory-practice/implement/count.test.js
index 42baf4b4b..cf4d7c6ca 100644
--- a/Sprint-3/3-mandatory-practice/implement/count.test.js
+++ b/Sprint-3/3-mandatory-practice/implement/count.test.js
@@ -22,3 +22,9 @@ test("should count multiple occurrences of a character", () => {
 // And a character char that does not exist within the case-sensitive str,
 // When the function is called with these inputs,
 // Then it should return 0, indicating that no occurrences of the char were found in the case-sensitive str.
+test("should return 0 when the character does not occur in the string", () => {
+  const str = "bbbbbb";
+  const char = "a";
+  const count = countChar(str, char);
+  expect(count).toEqual(0);
+});
diff --git a/Sprint-3/3-mandatory-practice/implement/get-ordinal-number.js b/Sprint-3/3-mandatory-practice/implement/get-ordinal-number.js
index 24f528b0d..10be0a29f 100644
--- a/Sprint-3/3-mandatory-practice/implement/get-ordinal-number.js
+++ b/Sprint-3/3-mandatory-practice/implement/get-ordinal-number.js
@@ -1,5 +1,11 @@
 function getOrdinalNumber(num) {
- return "1st";
+    let oneDigit = num % 10;
+    let twoDigit = num % 100;
+    if (twoDigit >= 11 && twoDigit <= 13 ) return `${num}th`;
+    else if (oneDigit == 1) return `${num}st`;
+    else if (oneDigit == 2) return `${num}nd`;
+    else if (oneDigit == 3) return `${num}rd`;
+    else return `${num}th`;
 }
 
 module.exports = getOrdinalNumber;
\ No newline at end of file
diff --git a/Sprint-3/3-mandatory-practice/implement/get-ordinal-number.test.js b/Sprint-3/3-mandatory-practice/implement/get-ordinal-number.test.js
index 6d55dfbb4..5c092596b 100644
--- a/Sprint-3/3-mandatory-practice/implement/get-ordinal-number.test.js
+++ b/Sprint-3/3-mandatory-practice/implement/get-ordinal-number.test.js
@@ -6,8 +6,55 @@ const getOrdinalNumber = require("./get-ordinal-number");
 
 // Case 1: Identify the ordinal number for 1
 // When the number is 1,
-// Then the function should return "1st"
+// Then the function should return "num+st"
+test("works for any number ending in 1", () => {
+  expect(getOrdinalNumber(1)).toEqual("1st");
+  expect(getOrdinalNumber(41)).toEqual("41st");
+  expect(getOrdinalNumber(51)).toEqual("51st");
+  expect(getOrdinalNumber(91)).toEqual("91st");
+});
 
-test("should return '1st' for 1", () => {
-    expect(getOrdinalNumber(1)).toEqual("1st");
-    });
+// Case 2: Identify the ordinal number for 2
+// When the number is 2,
+// Then the function should return "num+nd"
+test("works for any number ending in 2", () => {
+  expect(getOrdinalNumber(2)).toEqual("2nd");
+  expect(getOrdinalNumber(22)).toEqual("22nd");
+  expect(getOrdinalNumber(52)).toEqual("52nd");
+  expect(getOrdinalNumber(72)).toEqual("72nd");
+});
+
+// Case 3: Identify the ordinal number for 3
+// When the number is 3,
+// Then the function should return "3rd"
+test("works for any number ending in 3", () => {
+  expect(getOrdinalNumber(3)).toEqual("3rd");
+  expect(getOrdinalNumber(33)).toEqual("33rd");
+  expect(getOrdinalNumber(23)).toEqual("23rd");
+  expect(getOrdinalNumber(63)).toEqual("63rd");
+});
+
+// Case 4: Identify the ordinal number for 11, 12, 13
+// When the number is num = 11, 12, 13
+// Then the function should return "11st", "12nd", "13rd",
+test("should return 'num th' for num", () => {
+  expect(getOrdinalNumber(11)).toEqual("11th");
+  expect(getOrdinalNumber(12)).toEqual("12th");
+  expect(getOrdinalNumber(13)).toEqual("13th");
+});
+
+// Case 5: Identify the ordinal number for any number not covered above, up to 100
+// When the number is num = 4, 5,.... , 100
+// Then the function should return "4th", "5th", "6th", "7th", "8th", "9th", "10th", "55th", ...
+test("should return 'num th' for num", () => {
+  expect(getOrdinalNumber(4)).toEqual("4th");
+  expect(getOrdinalNumber(5)).toEqual("5th");
+  expect(getOrdinalNumber(6)).toEqual("6th");
+  expect(getOrdinalNumber(7)).toEqual("7th");
+  expect(getOrdinalNumber(8)).toEqual("8th");
+  expect(getOrdinalNumber(9)).toEqual("9th");
+  expect(getOrdinalNumber(10)).toEqual("10th");
+  expect(getOrdinalNumber(55)).toEqual("55th");
+  expect(getOrdinalNumber(46)).toEqual("46th");
+  expect(getOrdinalNumber(77)).toEqual("77th");
+});
diff --git a/Sprint-3/3-mandatory-practice/implement/repeat.js b/Sprint-3/3-mandatory-practice/implement/repeat.js
index 621f9bd35..d89df1f35 100644
--- a/Sprint-3/3-mandatory-practice/implement/repeat.js
+++ b/Sprint-3/3-mandatory-practice/implement/repeat.js
@@ -1,5 +1,8 @@
-function repeat() {
-    return "hellohellohello";
+function repeat(str, count) {
+  if (count == 1) return `${str}`;
+  else if (count == 0) return "";
+  else if (count < 0) return "negative counts are not valid";
+  else return `${str.repeat(count)}`;
 }
 
-module.exports = repeat;
\ No newline at end of file
+module.exports = repeat;
diff --git a/Sprint-3/3-mandatory-practice/implement/repeat.test.js b/Sprint-3/3-mandatory-practice/implement/repeat.test.js
index 8a4ab42ef..8eaa7e161 100644
--- a/Sprint-3/3-mandatory-practice/implement/repeat.test.js
+++ b/Sprint-3/3-mandatory-practice/implement/repeat.test.js
@@ -10,23 +10,44 @@ const repeat = require("./repeat");
 // Then it should repeat the str count times and return a new string containing the repeated str values.
 
 test("should repeat the string count times", () => {
-    const str = "hello";
-    const count = 3;
-    const repeatedStr = repeat(str, count);
-    expect(repeatedStr).toEqual("hellohellohello");
-    });
+  const str = "hello";
+  const count = 3;
+  const repeatedStr = repeat(str, count);
+  expect(repeatedStr).toEqual("hellohellohello");
+});
 
 // case: handle Count of 1:
 // Given a target string str and a count equal to 1,
 // When the repeat function is called with these inputs,
 // Then it should return the original str without repetition, ensuring that a count of 1 results in no repetition.
 
+test("should not repeat the string", () => {
+  const str = "hello";
+  const count = 1;
+  const repeatedStr = repeat(str, count);
+  expect(repeatedStr).toEqual("hello");
+});
+
 // case: Handle Count of 0:
 // Given a target string str and a count equal to 0,
 // When the repeat function is called with these inputs,
 // Then it should return an empty string, ensuring that a count of 0 results in an empty output.
 
+test("should not repeat the string", () => {
+  const str = "hello";
+  const count = 0;
+  const repeatedStr = repeat(str, count);
+  expect(repeatedStr).toEqual("");
+});
+
 // case: Negative Count:
 // Given a target string str and a negative integer count,
 // When the repeat function is called with these inputs,
 // Then it should throw an error or return an appropriate error message, as negative counts are not valid.
+
+test("should not repeat the string", () => {
+  const str = "hello";
+  const count = -1;
+  const repeatedStr = repeat(str, count);
+  expect(repeatedStr).toEqual("negative counts are not valid");
+});
diff --git a/Sprint-3/4-stretch-investigate/card-validator.js b/Sprint-3/4-stretch-investigate/card-validator.js
new file mode 100644
index 000000000..4582b7997
--- /dev/null
+++ b/Sprint-3/4-stretch-investigate/card-validator.js
@@ -0,0 +1,55 @@
+function cardNumberValidator(cardNumber) {
+  if (cardNumber.length !== 16) {
+    return false;
+  }
+  const numberInArray = cardNumber.toString().split(""); // convert the cardNumber to sting then into an array
+  // check if all numbers are numbers
+  let isAllNumbers = true;
+  for (let index = 0; index <= numberInArray.length - 1; index++) {
+    const currentNumber = numberInArray[index];
+    if (isNaN(currentNumber)) {
+      isAllNumbers = false;
+      break;
+    }
+  }
+  if (!isAllNumbers) {
+    return false; // Not all digits are numbers
+  }
+  // check if at least two different digits present (all of the digits cannot be the same)
+  let hasDifferentDigits = false;
+  for (let i = 1; i < numberInArray.length; i++) {
+    if (numberInArray[i] !== numberInArray[0]) {
+      hasDifferentDigits = true;
+      break;
+    }
+  }
+  if (!hasDifferentDigits) {
+    return false; // all digits are the same
+  }
+  // check if sum of all the digits are greater than 16.
+    let sum = 0;
+    for (let i = 0; i < numberInArray.length; i++) {
+      sum += Number(numberInArray[i]);
+    }
+    if (sum <= 16) {
+      return false; // the sum is not greater than 16
+    }
+    // check if the final digit is even.
+    let lastDigit = numberInArray[numberInArray.length - 1] % 2;
+    if (lastDigit !== 0) {
+      return false;
+    }
+    return true;
+}
+
+module.exports = cardNumberValidator;
+
+/*
+pseudocode:
+create a function to validate the card number.
+Number must be 16 digits, 
+All numbers must be numbers.
+You must have at least two different digits represented (all of the digits cannot be the same).
+The sum of all the digits must be greater than 16.
+The final digit must be even.
+*/
diff --git a/Sprint-3/4-stretch-investigate/card-validator.test.js b/Sprint-3/4-stretch-investigate/card-validator.test.js
new file mode 100644
index 000000000..41d08dfbd
--- /dev/null
+++ b/Sprint-3/4-stretch-investigate/card-validator.test.js
@@ -0,0 +1,32 @@
+// Implement a function cardNumberValidator
+const cardNumberValidator = require("./card-validator");
+
+// Given a cardNumber string and a positive integer count,
+// When the repeat function is called with these inputs,
+// Then it should:
+
+// case 1: check the card number has 16 digits
+test("card number should be 16 digits", () => {
+    expect(cardNumberValidator(12345678901234560)).toEqual(false);
+});
+
+// case 2: check all digits of the card number has to be numbers.
+test("card number should contains only numeric digits", () => {
+    expect(cardNumberValidator("a1111111b1111111")).toEqual(false);
+});
+
+// case 3: check the card number has at least 2 different digits
+test("card number should have at least 2 different digits", () => {
+    expect(cardNumberValidator("1111111111111111")).toEqual(false);
+});
+
+// case 4: check the card number has at least 2 different digits
+test("The sum of all digits should be grater than 16", () => {
+    expect(cardNumberValidator("0000000000000022")).toEqual(false);
+});
+
+// case 5: check the card number has at least 2 different digits
+test("The final digits should be even", () => {
+    expect(cardNumberValidator("1234567891234561")).toEqual(false);
+});
+
diff --git a/Sprint-3/4-stretch-investigate/find.js b/Sprint-3/4-stretch-investigate/find.js
index c7e79a2f2..18e868665 100644
--- a/Sprint-3/4-stretch-investigate/find.js
+++ b/Sprint-3/4-stretch-investigate/find.js
@@ -20,6 +20,12 @@ console.log(find("code your future", "z"));
 // Pay particular attention to the following:
 
 // a) How the index variable updates during the call to find
+//      index variable updated using the increment index++
 // b) What is the if statement used to check
+//      if statement check if the str[index] === char value which is 'u'
+//      let's say str[0] means st[0] == c so, if compares if 
+//      c === u it will return the index value which is the index of that letter.
 // c) Why is index++ being used?
+//      index++ used to increase the value of the index by 1 if the 'if condition' is false 
 // d) What is the condition index < str.length used for?
+//      index < str.length used to check that the index value still less than the length of the string