diff --git a/solutions/typescript/leap/1/leap.ts b/solutions/typescript/leap/1/leap.ts
new file mode 100644
index 0000000..c08cc84
--- /dev/null
+++ b/solutions/typescript/leap/1/leap.ts
@@ -0,0 +1,3 @@
+export function isLeap(year:number):boolean {
+  return (year%400 === 0) || (year%100 != 0 && year%4 === 0);
+}