diff --git a/src/factorial.js b/src/factorial.js
index 4f3ae70..35cab6c 100644
--- a/src/factorial.js
+++ b/src/factorial.js
@@ -1,5 +1,9 @@
 const factorial = (number) => {
-  // your code here
+  if (number == 0) {
+    return 1;
+  } else {
+    return number * factorial(number - 1);
+  }
 }
 
-module.exports = factorial;
\ No newline at end of file
+module.exports = factorial;
diff --git a/src/fibonacci.js b/src/fibonacci.js
index ea3270f..977ee5c 100644
--- a/src/fibonacci.js
+++ b/src/fibonacci.js
@@ -1,5 +1,9 @@
 const fibonacci = (n) => {
-  // your code here
+  let listNumbers = [0, 1];
+  for (let index = 2; index < n; index++) {
+    listNumbers.push(listNumbers[index - 1] + listNumbers[index-2]);
+  }
+  return listNumbers;
 }
 
-module.exports = fibonacci;
\ No newline at end of file
+module.exports = fibonacci;
diff --git a/src/primalidad.js b/src/primalidad.js
index 8bdb849..10f4cbb 100644
--- a/src/primalidad.js
+++ b/src/primalidad.js
@@ -1,5 +1,16 @@
-const trialDivision = (number) => {
-  // your code here
-}
+const trialDivision =
+    (number) => {
+      result = true;
+      if (number == 1) {
+        result = false;
+      } else {
+        for (let i = 2; i <= parseInt(Math.sqrt(number)); i++) {
+          if (number % i == 0) {
+            result = false;
+          }
+        }
+      }
+      return result;
+    }
 
-module.exports = trialDivision;
\ No newline at end of file
+module.exports = trialDivision;