diff --git a/src/sandbox.ts b/src/sandbox.ts
index 534d3b8..172c8ec 100644
--- a/src/sandbox.ts
+++ b/src/sandbox.ts
@@ -16,8 +16,8 @@ const add = (a: number, b: number, c/*?*/: number | string = 10): void => {
 add(5, 10, 'ninja');
 
 const minus = (a: number, b: number): number => {
-  return a + b;
+  return a - b;
 }
 
 let result = minus(10,7);
-console.log(result);
\ No newline at end of file
+console.log(result);