diff --git a/ipynb/Fred Buns.ipynb b/ipynb/Fred Buns.ipynb
index 1e0c8d0..72e4948 100644
--- a/ipynb/Fred Buns.ipynb	
+++ b/ipynb/Fred Buns.ipynb	
@@ -43,7 +43,7 @@
     "\n",
     "* **Lock**: For our purposes a lock can be modeled as a `list` of 4 **tumblers**. \n",
     "* **Tumbler:** Each tumbler has  10 distinct letters. I will represent a tumbler as a `str` of 10 letters.\n",
-    "* **Combination**: Choosing a letter from each tumbler gives a combination, such as \"FRED\" or \"BUNS\". There are 4<sup>10</sup> = 10,000 combinations.\n",
+    "* **Combination**: Choosing a letter from each tumbler gives a combination, such as \"FRED\" or \"BUNS\". There are 10<sup>4</sup> = 10,000 combinations.\n",
     "* **Word**: Some combinations (such as \"BUNS\") are *words*; others (such as \"SOMN\") are not words. We'll need a collection of dictionary words.\n",
     "\n",
     "Now on to the code!  First the imports I will need and the vocabulary concepts:"