diff --git a/session-01/validators.js b/session-01/validators.js
index 56ea66d..48be9c3 100644
--- a/session-01/validators.js
+++ b/session-01/validators.js
@@ -7,7 +7,15 @@
   - username cannot contain special characters
 */
 function validUsername(username) {
-  return;
+  if(username.length < 3 || username.length > 10)
+      return false;
+  if (!/^[a-zA-Z]/.test(username.charAt(0))) 
+    return false;
+
+  if (!/^[a-zA-Z0-9]+$/.test(username)) 
+    return false;
+
+  return true;
 }
 
 /*
@@ -17,7 +25,14 @@ function validUsername(username) {
   - password must contain at least 1 letter, 1 number, and 1 special character
 */
 function validPassword(password) {
-  return;
+  if(password.length < 10 || password.length > 64 )
+      return false; 
+  
+  let hasLetter = /[a-zA-Z]/.test(password);
+  let hasNumber = /[0-9]/.test(password);
+  let hasSpecialCharacter = /[^a-zA-Z0-9]/.test(password)
+
+  return hasLetter && hasNumber && hasSpecialCharacter;
 }
 
 module.exports = { validUsername, validPassword };
diff --git a/session-02/exercise.js b/session-02/exercise.js
index 6ade818..32632cf 100644
--- a/session-02/exercise.js
+++ b/session-02/exercise.js
@@ -3,7 +3,12 @@
   For example, for the input ["cat", "hat"], return ["CAT", "HAT"]
 */
 function transformArrayToUpper(listOfStrings) {
-  return;
+  for(let i = 0; i < listOfStrings.length; i++){
+    let words = listOfStrings[i];
+    listOfStrings[i] = words.toUpperCase();
+  }
+  console.log(listOfStrings);
+  return listOfStrings;
 }
 
 /*
@@ -16,7 +21,14 @@ function transformArrayToUpper(listOfStrings) {
     the function should return 51
 */
 function sumOfAllAges(listOfStudentObjects) {
-  return;
+  let sum = 0;
+  for(let i = 0; i < listOfStudentObjects.length; i++){
+    let age = listOfStudentObjects[i].age;
+    if(typeof age === 'number')
+      sum += age;
+  }
+  console.log(sum);
+  return sum;
 }
 
 module.exports = { transformArrayToUpper, sumOfAllAges };