diff --git a/Exercises/1-random.js b/Exercises/1-random.js
index ef5ccaf..9c7e590 100644
--- a/Exercises/1-random.js
+++ b/Exercises/1-random.js
@@ -1,9 +1,11 @@
 'use strict';
-
+const { random: frandom, floor: trunc } = Math;
 const random = (min, max) => {
-  // Generate random Number between from min to max
-  // Use Math.random() and Math.floor()
-  // See documentation at MDN
+  if (typeof(max) === 'undefined') {
+    max = min;
+    min = 0;
+  }
+  return trunc((max - min + 1) * frandom() + min);
 };
 
 module.exports = { random };
diff --git a/Exercises/2-key-short.js b/Exercises/2-key-short.js
new file mode 100644
index 0000000..cc33bde
--- /dev/null
+++ b/Exercises/2-key-short.js
@@ -0,0 +1,10 @@
+'use strict';
+const generateKey = (length, possible) => {
+  let s = '';
+  for (let i = 0; i < length; i++) {
+    s += possible[Math.floor(Math.random() * length)];
+  }
+  return s;
+};
+
+module.exports = { generateKey };
diff --git a/Exercises/2-key.js b/Exercises/2-key.js
index ba7e53a..a752487 100644
--- a/Exercises/2-key.js
+++ b/Exercises/2-key.js
@@ -1,9 +1,12 @@
 'use strict';
-
+const { random: frandom, floor: trunc } = Math;
 const generateKey = (length, possible) => {
-  // Generate string of random characters
-  // Use Math.random() and Math.floor()
-  // See documentation at MDN
+  let s = '';
+  const plength = possible.length;
+  for (let i = 0; i < length; i++) {
+    s += possible[trunc(frandom() * plength)];
+  }
+  return s;
 };
 
 module.exports = { generateKey };
diff --git a/Exercises/3-ip.js b/Exercises/3-ip.js
index 5b448dd..287446c 100644
--- a/Exercises/3-ip.js
+++ b/Exercises/3-ip.js
@@ -1,11 +1,14 @@
 '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 intNumber = str => parseInt(str, 10);
+const shiftEight = (num, index, array) => {
+  for (let i = 1; i < array.length - index; i++)
+    num <<= 8;
+  return num;
 };
+const sumArray = (sum, current) => sum + current;
+const ipToInt = (ip = '127.0.0.1') => ip.split('.')
+  .map(intNumber)
+  .map(shiftEight)
+  .reduce(sumArray);
 
 module.exports = { ipToInt };
diff --git a/Exercises/4-methods.js b/Exercises/4-methods.js
index c1038e8..3e11dbd 100644
--- a/Exercises/4-methods.js
+++ b/Exercises/4-methods.js
@@ -1,21 +1,10 @@
 '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 array = [];
+  for (const key in iface)
+    if (key === 'function') array.push([key, iface[key].length]);
+  return array;
 };
 
 module.exports = { methods };