diff --git a/Solutions to Chapter 9 Learning Aides.ipynb b/Solutions to Chapter 9 Learning Aides.ipynb
index a9c0618..a97eb93 100644
--- a/Solutions to Chapter 9 Learning Aides.ipynb	
+++ b/Solutions to Chapter 9 Learning Aides.ipynb	
@@ -1764,7 +1764,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Problem 9.11\n",
+    "#### Problem 9.11 TODO\n",
     "\n",
     "* (a) For fixed $d_{eff}$, when the order increases, $\\lambda$ should increase to keep the effective degree of freedom down."
    ]