diff --git a/ml2/3_5_Exercise_1.ipynb b/ml2/3_5_Exercise_1.ipynb
index 76920c7..80dcc56 100644
--- a/ml2/3_5_Exercise_1.ipynb
+++ b/ml2/3_5_Exercise_1.ipynb
@@ -46,7 +46,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "metadata": {
     "collapsed": true
    },
@@ -83,7 +83,7 @@
    "cell_type": "code",
    "execution_count": null,
    "metadata": {
-    "collapsed": true
+    "collapsed": false
    },
    "outputs": [],
    "source": []
@@ -420,11 +420,11 @@
    "source": [
     "# Group ages to simplify machine learning algorithms.  0: 0-5, 1: 6-10, 2: 11-15, 3: 16-59 and 4: 60-80\n",
     "df['AgeGroup'] = 0\n",
-    "df.loc[(.AgeFill<6),'AgeGroup'] = 0\n",
-    "df.loc[(df.AgeFill>=6) & (df.AgeFill < 11),'AgeGroup'] = 1\n",
-    "df.loc[(df.AgeFill>=11) & (df.AgeFill < 16),'AgeGroup'] = 2\n",
-    "df.loc[(df.AgeFill>=16) & (df.AgeFill < 60),'AgeGroup'] = 3\n",
-    "df.loc[(df.AgeFill>=60),'AgeGroup'] = 4"
+    "df.loc[(.Age<6),'AgeGroup'] = 0\n",
+    "df.loc[(df.Age>=6) & (df.Age < 11),'AgeGroup'] = 1\n",
+    "df.loc[(df.Age>=11) & (df.Age < 16),'AgeGroup'] = 2\n",
+    "df.loc[(df.Age>=16) & (df.Age < 60),'AgeGroup'] = 3\n",
+    "df.loc[(df.Age>=60),'AgeGroup'] = 4"
    ]
   },
   {
@@ -437,18 +437,22 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 8,
    "metadata": {
     "collapsed": false
    },
    "outputs": [],
    "source": [
     "def substrings_in_string(big_string, substrings):\n",
+    "    if type(big_string) == float:\n",
+    "        if np.isnan(big_string):\n",
+    "            return 'X'\n",
     "    for substring in substrings:\n",
     "        if big_string.find(substring) != 1:\n",
-    "           return substring\n",
+    "            return substring\n",
     "    print(big_string)\n",
-    "    return np.nan\n",
+    "    return 'X'\n",
+    " \n",
     "#Turning cabin number into Deck\n",
     "cabin_list = ['A', 'B', 'C', 'D', 'E', 'F', 'T', 'G', 'Unknown']\n",
     "df['Deck']=df['Cabin'].map(lambda x: substrings_in_string(x, cabin_list))"
@@ -537,7 +541,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.5.1+"
+   "version": "3.5.2"
   }
  },
  "nbformat": 4,