diff --git a/src/factorial.js b/src/factorial.js
index 4f3ae70..5c6e4fa 100644
--- a/src/factorial.js
+++ b/src/factorial.js
@@ -1,5 +1,12 @@
 const factorial = (number) => {
   // your code here
+  if (number === 0 || number === 1) {
+    return 1
+  }
+  else {
+    return(number * factorial(number - 1))
+  }
+  
 }
 
 module.exports = factorial;
\ No newline at end of file
diff --git a/src/fibonacci.js b/src/fibonacci.js
index ea3270f..17b0a16 100644
--- a/src/fibonacci.js
+++ b/src/fibonacci.js
@@ -1,5 +1,12 @@
 const fibonacci = (n) => {
   // your code here
+  if (n === 0 || n === 1) {
+    return n
+  }
+  else {
+    return(fibonacci(n-1) * fibonacci(n - 2))
+  }
+  
 }
 
 module.exports = fibonacci;
\ No newline at end of file
diff --git a/src/primalidad.js b/src/primalidad.js
index 8bdb849..341e90c 100644
--- a/src/primalidad.js
+++ b/src/primalidad.js
@@ -1,5 +1,15 @@
 const trialDivision = (number) => {
   // your code here
+  let flag = true
+
+  for (i = 2; i < Math.trunc(number/2); i++) {
+    if (number % i === 0) {
+      flag = false
+      break;
+    }
+  }
+
+  return flag
 }
 
 module.exports = trialDivision;
\ No newline at end of file