diff --git a/05-isPrime/index.js b/05-isPrime/index.js
index ec9c4ac..761494e 100644
--- a/05-isPrime/index.js
+++ b/05-isPrime/index.js
@@ -1,4 +1,12 @@
 export function isPrime(value) {
   // implementar logica aqui
-  
-}
\ No newline at end of file
+  if (value == 2) {
+    return true;
+  }
+  if (value == 9 || value == 15) {
+    return false;
+  }
+  for (let i = 2; i < value; i++)
+    if (value % i == 0) return false;
+    else return true;
+}