diff --git a/intro_python.ipynb b/intro_python.ipynb
index 0401968..14b6e58 100644
--- a/intro_python.ipynb
+++ b/intro_python.ipynb
@@ -112,22 +112,34 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 6,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "skip"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "int"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
     "# Numbers\n",
     "\n",
     "x = 3\n",
-    "y = 3.2"
+    "y = 3.2\n",
+    "\n",
+    "type(x)"
    ]
   },
   {
@@ -135,7 +147,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -155,7 +166,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -175,7 +185,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -194,7 +203,7 @@
    "metadata": {
     "ein.tags": "worksheet-0",
     "slideshow": {
-     "slide_type": "-"
+     "slide_type": "slide"
     }
    },
    "source": [
@@ -206,6 +215,7 @@
     "# Assignment\n",
     "a = 10      # 10\n",
     "\n",
+    "\n",
     "# Increment/Decrement\n",
     "a += 1      # 11\n",
     "a -= 1      # 10\n",
@@ -267,17 +277,34 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 3,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "7.5\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "True"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
     "# Printing - note how Jupyter automatically prints \"y\" to \"out\", \n",
     "# but we need to manually print \"x\" if we want to see it!\n",
@@ -308,10 +335,9 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -332,7 +358,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -353,7 +378,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -424,25 +448,38 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 12,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "high\n"
+     ]
+    }
+   ],
    "source": [
     "# Practise control flow: \n",
     "# write some code that prints \"high\" if\n",
     "# the number in x is greater than 5, and \"low\"\n",
     "# if the number is less than 5\n",
     "\n",
-    "x = 5\n",
+    "x = 6\n",
     "\n",
+    "if x > 5:\n",
+    "    print(\"high\")\n",
+    "    if x < 5:\n",
+    "        print(\"low\")\n",
+    "else:\n",
+    "        print(\"equal\")\n",
     "# your code here! Hint: use if/else and print."
    ]
   },
@@ -506,25 +543,38 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 24,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "This persons age is:  1\n",
+      "This persons age is:  2\n",
+      "This persons age is:  10\n",
+      "Done\n",
+      "This persons age is:  100\n"
+     ]
+    }
+   ],
    "source": [
     "# A list!\n",
     "ages = [1, 2, 10, None, 100]\n",
-    "\n",
     "# A loop! (note the indentation)\n",
     "for x in ages:\n",
-    "    print(\"This persons age is: \", x)\n",
-    "print(\"Done\")"
+    "    if x is not None:\n",
+    "        print(\"This persons age is: \", x)\n",
+    "    else:\n",
+    "\n",
+    "        print(\"Done\")"
    ]
   },
   {
@@ -532,7 +582,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -622,7 +671,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -649,7 +697,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -663,7 +710,7 @@
     "\n",
     "nums = [30,1,4,3,10.5,100]\n",
     "\n",
-    "min_num = x[0] \n",
+    "min_num = num[0] \n",
     "\n",
     "for num in nums: \n",
     "    if num < min_num:\n",
@@ -674,17 +721,27 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 29,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "5"
+      ]
+     },
+     "execution_count": 29,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
     "# Challenge!\n",
     "\n",
@@ -696,24 +753,35 @@
     "total = 0 \n",
     "\n",
     "for num in nums:\n",
-    "    # Your code here\n",
+    "    if num is not None:\n",
+    "        total += 1\n",
     "    \n",
     "total"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 30,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[900, 1, 16, 9, 110.25, 10000]"
+      ]
+     },
+     "execution_count": 30,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
     "# Applying a function: \n",
     "# Squaring each number in a list\n",
@@ -733,7 +801,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -756,17 +823,27 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 31,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[21, 45, 97]"
+      ]
+     },
+     "execution_count": 31,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
     "# Filter:\n",
     "# Remove all values less than 18:\n",
@@ -783,7 +860,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -849,17 +925,26 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 32,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "om has scored 100 points\n",
+      "nandan has scored 10000 points\n",
+      "arapakis has scored 55 points\n"
+     ]
+    }
+   ],
    "source": [
     "# Destructuring tuples in a for loop:\n",
     "\n",
@@ -874,17 +959,27 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 37,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'nandan'"
+      ]
+     },
+     "execution_count": 37,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
     "# Aggregating a list of tuples: \n",
     "\n",
@@ -894,7 +989,16 @@
     "\n",
     "scoreboard = [(\"om\", 100), (\"nandan\", 10000), (\"arapakis\", 55)]\n",
     "\n",
-    "# Your code here"
+    "# Your code here\n",
+    "highest = \"name\"\n",
+    "highests = 0\n",
+    "\n",
+    "for name,score in scoreboard:\n",
+    "    if score > highests:\n",
+    "        highest = name\n",
+    "        highests = score\n",
+    "\n",
+    "highest\n"
    ]
   },
   {
@@ -936,17 +1040,24 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 57,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "[['statistics', 'more statistics', 'even more statistics'], ['ice cream'], ['R', 'D3']]\n"
+     ]
+    }
+   ],
    "source": [
     "# Challenge: \n",
     "# Collect all the likes of the teachers into one list: \n",
@@ -959,7 +1070,15 @@
     "            {\"name\": \"nandan\", \"score\": 10000, \"likes\": [\"ice cream\"]},\n",
     "            {\"name\": \"arapakis\", \"score\": 55, \"likes\": [\"R\", \"D3\"]}]\n",
     "\n",
-    "# Your code here"
+    "# Your code here\n",
+    "likes = []\n",
+    "\n",
+    "#for k in teachers:\n",
+    "#    likes = likes + k[\"likes\"]\n",
+    "\n",
+    "   \n",
+    "likes = [teachers[\"likes\"] for teachers in teachers]\n",
+    "print(likes)\n"
    ]
   },
   {
@@ -1011,25 +1130,44 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 73,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
      "slide_type": "-"
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "['hello,', 'i', 'would', 'like', 'a', 'foo.', 'foo', 'went', 'for', 'a', 'walk.', 'foo', 'bar', 'baz.', 'baz', 'to', 'foo', 'foo', 'the', 'foo.']\n",
+      "6\n"
+     ]
+    }
+   ],
    "source": [
     "# Challenge: \n",
     "# Count the instances of \"foo\" in the following text, \n",
     "# ignoring case:\n",
     "\n",
-    "x = \"Hello, I would like a foo. Foo went for a walk. Foo bar baz. Baz to the foo.\"\n",
+    "x = \"Hello, I would like a foo. Foo went for a walk. Foo bar baz. Baz to foo foo the foo.\"\n",
     "\n",
-    "# Your code here"
+    "# Your code here\n",
+    "count = 0\n",
+    "foo_list = x.lower().split(\" \")\n",
+    "\n",
+    "print(foo_list)\n",
+    "for word in foo_list:\n",
+    "    if \"foo\" in word:\n",
+    "        count += 1\n",
+    "\n",
+    "#count = len(x.lower().split(\"foo\")) - 1\n",
+    "\n",
+    "print(count)\n"
    ]
   },
   {
@@ -1090,7 +1228,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -1153,7 +1290,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -1174,7 +1310,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -1195,7 +1330,6 @@
    "execution_count": null,
    "metadata": {
     "autoscroll": false,
-    "collapsed": false,
     "ein.hycell": false,
     "ein.tags": "worksheet-0",
     "slideshow": {
@@ -1220,7 +1354,7 @@
     }
    },
    "source": [
-    "## Programming project: basic text analytics\n",
+    "# Programming project: basic text analytics\n",
     "\n",
     "Open the file \"textfile.txt\", which has copied a passage from the book Learning Python\". \n",
     "\n",
@@ -1233,27 +1367,13 @@
     "As a first step, and as a simpler exercise, do the above for a single paragraph of the text. Do this first and if you do not manage to finish the larger project submit this as your solution. \n",
     "\n"
    ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "autoscroll": false,
-    "collapsed": false,
-    "ein.hycell": false,
-    "ein.tags": "worksheet-0",
-    "slideshow": {
-     "slide_type": "-"
-    }
-   },
-   "outputs": [],
-   "source": []
   }
  ],
  "metadata": {
   "celltoolbar": "Slideshow",
   "kernelspec": {
    "display_name": "Python 3",
+   "language": "python",
    "name": "python3"
   },
   "language_info": {