diff --git a/sorting_searching/merge_sort/merge_sort_challenge.ipynb b/sorting_searching/merge_sort/merge_sort_challenge.ipynb
index 203b736..d22369d 100644
--- a/sorting_searching/merge_sort/merge_sort_challenge.ipynb
+++ b/sorting_searching/merge_sort/merge_sort_challenge.ipynb
@@ -35,6 +35,8 @@
     "## Constraints\n",
     "\n",
     "* Is a naiive solution sufficient?\n",
+    "    * Yes\n",
+    "* Are duplicates allowed?\n",
     "    * Yes"
    ]
   },
@@ -163,7 +165,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.4.3"
+   "version": "3.5.0"
   }
  },
  "nbformat": 4,
diff --git a/sorting_searching/merge_sort/merge_sort_solution.ipynb b/sorting_searching/merge_sort/merge_sort_solution.ipynb
index 41157e4..f6bb920 100644
--- a/sorting_searching/merge_sort/merge_sort_solution.ipynb
+++ b/sorting_searching/merge_sort/merge_sort_solution.ipynb
@@ -34,6 +34,8 @@
     "## Constraints\n",
     "\n",
     "* Is a naiive solution sufficient?\n",
+    "    * Yes\n",
+    "* Are duplicates allowed?\n",
     "    * Yes"
    ]
   },
@@ -118,7 +120,7 @@
     "    if data is None or len(data) < 2:\n",
     "        return data\n",
     "    mid = len(data) // 2\n",
-    "    left = data[0:mid]\n",
+    "    left = data[:mid]\n",
     "    right = data[mid:]\n",
     "    left = merge_sort(left)\n",
     "    right = merge_sort(right)\n",
@@ -227,7 +229,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.4.3"
+   "version": "3.5.0"
   }
  },
  "nbformat": 4,