diff --git a/04_iteration/01_exercises.ipynb b/04_iteration/01_exercises.ipynb
index cf4b0ce..08fe309 100644
--- a/04_iteration/01_exercises.ipynb
+++ b/04_iteration/01_exercises.ipynb
@@ -479,7 +479,7 @@
     "    if _offset is not None:\n",
     "        count += _offset\n",
     "\n",
-    "    # answer to Q18\n",
+    "    # answer to Q13\n",
     "    hanoi_ordered(..., _offset=_offset)\n",
     "    ...\n",
     "    hanoi_ordered(..., _offset=count)"