diff --git a/Exercises/1-let.js b/Exercises/1-let.js
index d705443..e1e92f5 100644
--- a/Exercises/1-let.js
+++ b/Exercises/1-let.js
@@ -1,5 +1,5 @@
 'use strict';
 
-let name = undefined;
+let name = 'Mykhailo';
 
 module.exports = { name };
diff --git a/Exercises/2-const.js b/Exercises/2-const.js
index 5512738..3202210 100644
--- a/Exercises/2-const.js
+++ b/Exercises/2-const.js
@@ -1,5 +1,5 @@
 'use strict';
 
-const year = undefined;
+const year = 2003;
 
 module.exports = { year };
diff --git a/Exercises/3-hello.js b/Exercises/3-hello.js
index a597391..091a6e5 100644
--- a/Exercises/3-hello.js
+++ b/Exercises/3-hello.js
@@ -1,5 +1,9 @@
 'use strict';
 
-const hello = null;
+
+const hello = (name) => {
+    console.log(`Hello, ${name}!`);
+};
+
 
 module.exports = { hello };
diff --git a/Exercises/4-range.js b/Exercises/4-range.js
index 31bd852..0e95888 100644
--- a/Exercises/4-range.js
+++ b/Exercises/4-range.js
@@ -1,5 +1,11 @@
 'use strict';
 
-const range = null;
+const range = (start, end) => {
+    const result = [];
+    for (let i = start; i <= end; i++) {
+        result.push(i);
+    }
+    return result;
+};
 
 module.exports = { range };
diff --git a/Exercises/5-range-odd.js b/Exercises/5-range-odd.js
index 54bb5b4..159a651 100644
--- a/Exercises/5-range-odd.js
+++ b/Exercises/5-range-odd.js
@@ -1,5 +1,14 @@
 'use strict';
 
-const rangeOdd = null;
+const rangeOdd = (start, end) => {
+    const result = [];
+    for (let i = start; i <= end; i++) {
+        if (i % 2 !== 0) {
+            result.push(i);
+        }
+    }
+    return result;
+};
+
 
 module.exports = { rangeOdd };
diff --git a/Exercises/6-calculate.js b/Exercises/6-calculate.js
index dfecf6b..9aaa961 100644
--- a/Exercises/6-calculate.js
+++ b/Exercises/6-calculate.js
@@ -1,11 +1,23 @@
 'use strict';
 
-const square = null;
+const square = (x) => {
+    return x * x;
+};
 
-const cube = null;
+const cube = (x) => {
+    return x * x * x;
+};
 
-const average = null;
+const average = (a, b) => {
+    return (a + b) / 2;
+};
 
-const calculate = null;
+const calculate = () => {
+    const results = [];
+    for (let i = 0; i <= 9; i++) {
+        results.push(average(square(i), cube(i)));
+    }
+    return results;
+};
 
 module.exports = { square, cube, average, calculate };
diff --git a/Exercises/7-objects.js b/Exercises/7-objects.js
index 0920026..a103629 100644
--- a/Exercises/7-objects.js
+++ b/Exercises/7-objects.js
@@ -1,5 +1,20 @@
 'use strict';
 
-const fn = null;
+const fn = () => {
+    const objConst = { name: 'Constant Object//' };
+  
+    let objVar = { name: 'Variable Object' };
+  
+    objConst.name = 'New Constant Object';
+    objVar.name = 'New Variable Object';
+  
+    
+    
+    objVar = { name: 'Another Variable Object' };
+  
+    
+    console.log(objConst);
+    console.log(objVar);
+  };
 
 module.exports = { fn };
diff --git a/Exercises/8-create.js b/Exercises/8-create.js
index ac27ddd..d7754b2 100644
--- a/Exercises/8-create.js
+++ b/Exercises/8-create.js
@@ -1,5 +1,7 @@
 'use strict';
 
-const createUser = null;
+const createUser = (name, city) => {
+    return { name, city };
+};
 
 module.exports = { createUser };
diff --git a/Exercises/9-array.js b/Exercises/9-array.js
index 466c69a..2641021 100644
--- a/Exercises/9-array.js
+++ b/Exercises/9-array.js
@@ -1,7 +1,18 @@
 'use strict';
 
-const phonebook = null;
+const phonebook = [
+    { name: 'Marcus Aurelius', phone: '+380445554433' },
+    { name: 'Mykhailo Chubko', phone: '+38055554434' },
+    { name: 'Ksenii Mizina', phone: '+380555554435' }
+];
 
-const findPhoneByName = null;
+const findPhoneByName = (name) => {
+    for (const entry of phonebook) {
+        if (entry.name === name) {
+            return entry.phone;
+        }
+    }
+    return null;
+};
 
 module.exports = { phonebook, findPhoneByName };