diff --git a/Exercises/1-random.js b/Exercises/1-random.js
index ef5ccaf..529fd5c 100644
--- a/Exercises/1-random.js
+++ b/Exercises/1-random.js
@@ -1,9 +1,14 @@
 'use strict';
+// Generate random Number between from min to max
+// Use Math.random() and Math.floor()
+// See documentation at MDN
+
 
 const random = (min, max) => {
-  // Generate random Number between from min to max
-  // Use Math.random() and Math.floor()
-  // See documentation at MDN
+  const rand = Math.random();
+  const value = rand * (max - min + 1) + min;
+  const result = Math.floor(value);
+  return result;
 };
 
 module.exports = { random };
diff --git a/Exercises/2-key.js b/Exercises/2-key.js
index ba7e53a..99a76fa 100644
--- a/Exercises/2-key.js
+++ b/Exercises/2-key.js
@@ -1,9 +1,16 @@
 'use strict';
+// Generate string of random characters
+// Use Math.random() and Math.floor()
+// See documentation at MDN
 
 const generateKey = (length, possible) => {
-  // Generate string of random characters
-  // Use Math.random() and Math.floor()
-  // See documentation at MDN
+  let res = '';
+  for (let i = 0; i < length; i++) {
+    const ran = Math.floor(Math.random() * possible.length);
+    const ch = possible[ran];
+    res += ch;
+  }
+  return res;
 };
 
 module.exports = { generateKey };
diff --git a/Exercises/3-ip.js b/Exercises/3-ip.js
index 5b448dd..219f9d5 100644
--- a/Exercises/3-ip.js
+++ b/Exercises/3-ip.js
@@ -1,11 +1,18 @@
 'use strict';
 
+// Parse ip address as string, for example '10.0.0.1'
+// to ['10', '0', '0', '1'] to [10, 0, 0, 1]
+// and convert to Number value 167772161 with sitwise shift
+// (10 << 8 << 8 << 8) + (0 << 8 << 8) + (0 << 8) + 1 === 167772161
+// Use Array.prototype.reduce of for loop
+
+
 const ipToInt = (ip = '127.0.0.1') => {
-  // Parse ip address as string, for example '10.0.0.1'
-  // to ['10', '0', '0', '1'] to [10, 0, 0, 1]
-  // and convert to Number value 167772161 with sitwise shift
-  // (10 << 8 << 8 << 8) + (0 << 8 << 8) + (0 << 8) + 1 === 167772161
-  // Use Array.prototype.reduce of for loop
+  const ar = ip.split('.');
+  let res = 0;
+  for (let i = 0; i < ar.length; i++) res = (res << 8) + ar[i] * 1;
+  return res;
 };
 
+
 module.exports = { ipToInt };
diff --git a/Exercises/4-methods.js b/Exercises/4-methods.js
index c1038e8..8568b46 100644
--- a/Exercises/4-methods.js
+++ b/Exercises/4-methods.js
@@ -1,21 +1,29 @@
 'use strict';
 
+// Introspect all properties of iface object and
+// extract function names and number of arguments
+// For example: {
+//   m1: x => [x],
+//   m2: function (x, y) {
+//     return [x, y];
+//   },
+//   m3(x, y, z) {
+//     return [x, y, z];
+//   }
+// will return: [
+//   ['m1', 1],
+//   ['m2', 2],
+//   ['m3', 3]
+// ]
+
 const methods = iface => {
-  // Introspect all properties of iface object and
-  // extract function names and number of arguments
-  // For example: {
-  //   m1: x => [x],
-  //   m2: function (x, y) {
-  //     return [x, y];
-  //   },
-  //   m3(x, y, z) {
-  //     return [x, y, z];
-  //   }
-  // will return: [
-  //   ['m1', 1],
-  //   ['m2', 2],
-  //   ['m3', 3]
-  // ]
+  const result = [];
+  for (const name in iface) {
+    if (typeof iface[name] === 'function') {
+      result.push([name, iface[name].length]);
+    }
+  }
+  return result;
 };
 
 module.exports = { methods };