diff --git a/linked_lists/remove_duplicates/remove_duplicates_challenge.ipynb b/linked_lists/remove_duplicates/remove_duplicates_challenge.ipynb
index 35f851c..d67fd4a 100644
--- a/linked_lists/remove_duplicates/remove_duplicates_challenge.ipynb
+++ b/linked_lists/remove_duplicates/remove_duplicates_challenge.ipynb
@@ -38,7 +38,7 @@
     "\n",
     "* Is this a singly or doubly linked list?\n",
     "    * Singly\n",
-    "* Can you insert NULL values in the list?\n",
+    "* Can you insert None values in the list?\n",
     "    * No\n",
     "* Can you use additional data structures?\n",
     "    * Implement both solutions\n",
diff --git a/linked_lists/remove_duplicates/remove_duplicates_solution.ipynb b/linked_lists/remove_duplicates/remove_duplicates_solution.ipynb
index 8fc00c5..84c0c42 100644
--- a/linked_lists/remove_duplicates/remove_duplicates_solution.ipynb
+++ b/linked_lists/remove_duplicates/remove_duplicates_solution.ipynb
@@ -38,7 +38,7 @@
     "\n",
     "* Is this a singly or doubly linked list?\n",
     "    * Singly\n",
-    "* Can you insert NULL values in the list?\n",
+    "* Can you insert None values in the list?\n",
     "    * No\n",
     "* Can you use additional data structures?\n",
     "    * Implement both solutions\n",
@@ -72,7 +72,7 @@
     "\n",
     "Complexity:\n",
     "* Time: O(n)\n",
-    "* Space: O(m) where m is the number of values in the hash map\n",
+    "* Space: O(n)\n",
     "\n",
     "Note:\n",
     "* Deletion requires two pointers, one to the previous node and one to the current node"
@@ -93,7 +93,7 @@
     "\n",
     "Complexity:\n",
     "* Time: O(n^2)\n",
-    "* Space: In-place\n",
+    "* Space: O(1)\n",
     "\n",
     "Note:\n",
     "* Deletion requires two pointers, one to the previous node and one to the current node\n",