diff --git a/01/app.js b/01/app.js
index e69de29..3965d4e 100644
--- a/01/app.js
+++ b/01/app.js
@@ -0,0 +1,6 @@
+const users = ['Michal Wasiak', 'Adam Bedka','Karolina Konieczna','Wojtek Zapart','Antoni Waski','Michalina Kowalska'];
+
+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..7a032a7 100644
--- a/02/app.js
+++ b/02/app.js
@@ -11,13 +11,24 @@ console.log(randomArray);
 function createRandomArray() {
     const arr = [];
     const len = getRandomInteger(1, 10)
-    for(let i=0; i<len; i++) {
-        arr.push( getRandomInteger(1, 100) );
+    for (let i = 0; i < len; i++) {
+        arr.push(getRandomInteger(1, 100));
     }
 
     return arr;
 }
 
 function getRandomInteger(min, max) {
-    return Math.round(Math.random() * (max-min) + min);
-}
\ No newline at end of file
+    return Math.round(Math.random() * (max - min) + min);
+}
+
+for (let i = 0; i < randomArray.length; i++) {
+    console.log(randomArray[i]);
+}
+
+randomArray.forEach(function (element, index, array) {
+    console.log(element);
+});
+
+const lastIndex = randomArray.length-1;
+console.log('Ostatni element tablicy to: ' + randomArray[lastIndex]);
\ No newline at end of file
diff --git a/03/app.js b/03/app.js
index cebcbc2..a2f1c91 100644
--- a/03/app.js
+++ b/03/app.js
@@ -1,2 +1,11 @@
 const n = 24;
-const oddNumbers = [];
\ No newline at end of file
+const oddNumbers = [];
+console.log(oddNumbers);
+
+for (let i = 1; i <= n; i++) {
+    if (i % 2 !== 0) {
+        oddNumbers.push(i);
+    }
+}
+
+console.log(oddNumbers);
\ No newline at end of file
diff --git a/04/app.js b/04/app.js
index 8285afd..30f9e51 100644
--- a/04/app.js
+++ b/04/app.js
@@ -1 +1,9 @@
-const years = [1980, 1934, 2002, 2019];
\ No newline at end of file
+const years = [1980, 1934, 2002, 2019];
+const presentYear = 2025;
+const yearsDiff = years.map(diffBetweenYears);
+console.log(yearsDiff);
+
+
+function diffBetweenYears(element) {
+    return presentYear - element;
+}
\ No newline at end of file
diff --git a/05/app.js b/05/app.js
index 1c6bb90..e17babf 100644
--- a/05/app.js
+++ b/05/app.js
@@ -1 +1,6 @@
-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 evenNumbers = numbers.filter((item) => item % 2 === 0);
+const sum = evenNumbers.reduce((item, x) => item + x, 0)
+console.log(evenNumbers);
+console.log(sum);
+