diff --git a/01/app.js b/01/app.js
index e69de29..e2b05cd 100644
--- a/01/app.js
+++ b/01/app.js
@@ -0,0 +1,7 @@
+users = ['Jan Kowalski', 'Piotr Nowak', 'Zofia Kowalska', 'Anna Jankowska', 'Zygmunt Jakiś', 'Barbara Torba', 'Marianna Cymbał']
+
+console.log(users[0])
+console.log(users[2])
+console.log(users[4])
+
+console.log(users.length)
\ No newline at end of file
diff --git a/02/app.js b/02/app.js
index 9ad302b..b97ea96 100644
--- a/02/app.js
+++ b/02/app.js
@@ -20,4 +20,17 @@ function createRandomArray() {
 
 function getRandomInteger(min, max) {
     return Math.round(Math.random() * (max-min) + min);
-}
\ No newline at end of file
+}
+
+console.log("Wyświetlanie elementów tablicy za pomocą pętli `for`:");
+for (let i = 0; i < randomArray.length; i++) {
+    console.log(randomArray[i]);
+}
+
+console.log("Wyświetlanie elementów tablicy za pomocą metody `.forEach()`:");
+randomArray.forEach((element) => {
+    console.log(element);
+});
+
+const lastElement = randomArray[randomArray.length - 1];
+console.log("Ostatni element tablicy:", lastElement);
\ No newline at end of file
diff --git a/03/app.js b/03/app.js
index cebcbc2..82f5203 100644
--- a/03/app.js
+++ b/03/app.js
@@ -1,2 +1,10 @@
 const n = 24;
-const oddNumbers = [];
\ No newline at end of file
+const oddNumbers = [];
+
+for (let i = 1; i <= n; i++) {
+    if (i % 2 !== 0) { 
+        oddNumbers.push(i);
+    }
+}
+
+console.log("Tablica liczb nieparzystych:", oddNumbers);
\ No newline at end of file
diff --git a/04/app.js b/04/app.js
index 8285afd..573c016 100644
--- a/04/app.js
+++ b/04/app.js
@@ -1 +1,7 @@
-const years = [1980, 1934, 2002, 2019];
\ No newline at end of file
+const years = [1980, 1934, 2002, 2019];
+
+const currentYear = new Date().getFullYear(); 
+
+const yearsPassed = years.map(year => currentYear - year);
+
+console.log(yearsPassed);
\ No newline at end of file
diff --git a/05/app.js b/05/app.js
index 1c6bb90..30514a6 100644
--- a/05/app.js
+++ b/05/app.js
@@ -1 +1,8 @@
-const numbers = [1, 2, 3, 4, 5, 6, 7];
\ No newline at end of file
+const numbers = [1, 2, 3, 4, 5, 6, 7];
+
+
+const evenNumbersSum = numbers
+  .filter(number => number % 2 === 0)
+  .reduce((sum, number) => sum + number, 0);
+
+console.log(evenNumbersSum);
\ No newline at end of file