diff --git a/src/factorial.js b/src/factorial.js
index 4f3ae70..fc5c093 100644
--- a/src/factorial.js
+++ b/src/factorial.js
@@ -1,5 +1,10 @@
 const factorial = (number) => {
-  // your code here
+  let result = 1
+  while(number){
+    result *= number
+    number-=1
+  }
+  return result
 }
 
 module.exports = factorial;
\ No newline at end of file
diff --git a/src/fibonacci.js b/src/fibonacci.js
index ea3270f..14fd6d2 100644
--- a/src/fibonacci.js
+++ b/src/fibonacci.js
@@ -1,5 +1,12 @@
 const fibonacci = (n) => {
-  // your code here
+  let memo = [0,1]
+  while(n>1){
+    const nextFibo = memo[memo.length-1] + memo[memo.length-2]
+    memo.push(nextFibo)
+    n -= 1
+  }
+  memo.shift()
+  return memo
 }
 
 module.exports = fibonacci;
\ No newline at end of file
diff --git a/src/primalidad.js b/src/primalidad.js
index 8bdb849..d566b8b 100644
--- a/src/primalidad.js
+++ b/src/primalidad.js
@@ -1,5 +1,22 @@
 const trialDivision = (number) => {
-  // your code here
+  // validation of decimals
+  if(number != parseInt(number)) return false
+  // validation negativos
+  if(number <= 1) return false
+  // if it is 2 is correct
+  if(number == 2) return true
+
+  let min = 2;
+  let max = number;
+
+  while(min < max){
+    if(number % min==0){
+      return false;
+    }
+    max = parseInt(number/min)+1;
+    min += 1;
+  }
+  return true;
 }
 
 module.exports = trialDivision;
\ No newline at end of file