diff --git a/Exercises/1-random.js b/Exercises/1-random.js
index ef5ccaf..6653494 100644
--- a/Exercises/1-random.js
+++ b/Exercises/1-random.js
@@ -1,9 +1,6 @@
 'use strict';
 
-const random = (min, max) => {
-  // Generate random Number between from min to max
-  // Use Math.random() and Math.floor()
-  // See documentation at MDN
-};
+const random = (min = 0, max) =>  Math.floor(Math.random() * (max - min + 1) + min);
+
 
 module.exports = { random };
diff --git a/Exercises/1-random.test b/Exercises/1-random.test
index 15abbf9..7e5356c 100644
--- a/Exercises/1-random.test
+++ b/Exercises/1-random.test
@@ -1,6 +1,6 @@
 ({
   name: 'random',
-  length: [120, 150],
+  length: [20, 150],
   test: random => {
     const x = random(0, 10);
     if (typeof x !== 'number') throw new Error('Expected number result');
diff --git a/Exercises/2-key.js b/Exercises/2-key.js
index ba7e53a..8065a78 100644
--- a/Exercises/2-key.js
+++ b/Exercises/2-key.js
@@ -1,9 +1,14 @@
 'use strict';
-
-const generateKey = (length, possible) => {
-  // Generate string of random characters
-  // Use Math.random() and Math.floor()
-  // See documentation at MDN
+const generateKey = (leng, char) => {
+  let res = '';
+  let i = 0;
+  while (i < leng) {
+    let ba = char.length -1;
+    const ran = Math.floor(Math.random() * (ba + 1));
+    res += char[ran];
+    i++;
+  }
+  return res;
 };
 
 module.exports = { generateKey };
diff --git a/Exercises/3-ip.js b/Exercises/3-ip.js
index 5b448dd..0a596c4 100644
--- a/Exercises/3-ip.js
+++ b/Exercises/3-ip.js
@@ -1,11 +1,15 @@
 'use strict';
 
-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 ipToInt = (str = '127.0.0.1') => {
+  const a = str.split('.');
+  for (const i in a) {
+    a[i] = +a[i];
+  }
+  for (let i = 3, j = 0; i >= 0; i--, j++) {
+    a[j] = a[j] << 8 * i;
+  }
+  return a
+    .reduce((sum, cur) => sum + cur, 0);
 };
 
 module.exports = { ipToInt };
diff --git a/Exercises/3-ip.test b/Exercises/3-ip.test
index 6fb967b..27dc79f 100644
--- a/Exercises/3-ip.test
+++ b/Exercises/3-ip.test
@@ -1,6 +1,6 @@
 ({
   name: 'ipToInt',
-  length: [60, 150],
+  length: [60, 270],
   cases: [
     ['127.0.0.1', 2130706433],
     ['10.0.0.1', 167772161],
diff --git a/Exercises/4-methods.js b/Exercises/4-methods.js
index c1038e8..2c7bd59 100644
--- a/Exercises/4-methods.js
+++ b/Exercises/4-methods.js
@@ -1,21 +1,14 @@
 'use strict';
 
-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 methods = obj => {
+  const ans = [];
+  for (const key in obj) {
+    if (typeof obj[key] === 'function') {
+      ans
+        .push([key, obj[key].length]);
+    }
+  }
+  return ans;
 };
 
 module.exports = { methods };
diff --git a/Exercises/4-methods.test b/Exercises/4-methods.test
index a408b22..989e1a9 100644
--- a/Exercises/4-methods.test
+++ b/Exercises/4-methods.test
@@ -1,6 +1,6 @@
 ({
   name: 'methods',
-  length: [180, 220],
+  length: [20, 220],
   cases: [
     [
       {