diff --git a/online_judges/math_ops/math_ops_solution.ipynb b/online_judges/math_ops/math_ops_solution.ipynb
index 801f90c..c8ef0c8 100644
--- a/online_judges/math_ops/math_ops_solution.ipynb
+++ b/online_judges/math_ops/math_ops_solution.ipynb
@@ -58,7 +58,7 @@
     "* [5, 2, 7, 9, 9, 2, 9, 4, 3, 3, 2]\n",
     "    * max: 9\n",
     "    * min: 2\n",
-    "    * mean: 55\n",
+    "    * mean: 5\n",
     "    * mode: 9 or 2"
    ]
   },