diff --git a/1-js/05-data-types/05-array-methods/12-reduce-object/solution.md b/1-js/05-data-types/05-array-methods/12-reduce-object/solution.md
index e69de29bb2..2ba32862f7 100644
--- a/1-js/05-data-types/05-array-methods/12-reduce-object/solution.md
+++ b/1-js/05-data-types/05-array-methods/12-reduce-object/solution.md
@@ -0,0 +1,6 @@
+function groupById(arr) {
+  return arr.reduce((obj, value) => {
+    obj[value.id] = value;
+    return obj;
+  }, {})
+}