diff --git a/module3/exo3/exercice.ipynb b/module3/exo3/exercice.ipynb
index 77a2fc84d647710611780645d5d3e75c798a426f..8bdff6f453c56d0799fe7da3256a42aaedc5aa24 100644
--- a/module3/exo3/exercice.ipynb
+++ b/module3/exo3/exercice.ipynb
@@ -1067,6 +1067,7 @@
     }
    ],
    "source": [
+    "# create a barplot\n",
     "plt.bar(my_data[\"Year\"], my_data[\"Wheat\"])"
    ]
   },
@@ -1079,16 +1080,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 39,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "<matplotlib.collections.PolyCollection at 0x7f7af6d8aeb8>"
+       "<matplotlib.collections.PolyCollection at 0x7f7af173d898>"
       ]
      },
-     "execution_count": 7,
+     "execution_count": 39,
      "metadata": {},
      "output_type": "execute_result"
     },
@@ -1106,13 +1107,13 @@
     }
    ],
    "source": [
+    "# create a plot\n",
     "plt.plot(my_data[\"Year\"], my_data[\"Wages\"], \"r\")\n",
     "\n",
-    "    \n",
-    "y1 = my_data[\"Wages\"]\n",
-    "x = my_data[\"Year\"]\n",
-    "    \n",
-    "plt.fill_between(x, y1, color='#539ecd')"
+    "# fill area between curve and axis\n",
+    "x = my_data[\"Year\"]   \n",
+    "y = my_data[\"Wages\"]    \n",
+    "plt.fill_between(x, y, color='#539ecd')"
    ]
   },
   {
@@ -1124,16 +1125,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 43,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "<matplotlib.collections.PolyCollection at 0x7f7af6c8e198>"
+       "<matplotlib.collections.PolyCollection at 0x7f7af1e835c0>"
       ]
      },
-     "execution_count": 8,
+     "execution_count": 43,
      "metadata": {},
      "output_type": "execute_result"
     },
@@ -1151,17 +1152,14 @@
     }
    ],
    "source": [
+    "# create two plots in the same graph\n",
+    "p = plt.bar(my_data[\"Year\"], my_data[\"Wheat\"]), \n",
+    "plt.plot(my_data[\"Year\"], my_data[\"Wages\"], \"r\")\n",
     "\n",
-    "\n",
-    "p = plt.bar(my_data[\"Year\"], my_data[\"Wheat\"]), plt.plot(my_data[\"Year\"], my_data[\"Wages\"], \"r\")\n",
-    "\n",
-    "\n",
+    "# fill area between curve and axis\n",
     "x = my_data[\"Year\"]\n",
-    "y2 = my_data[\"Wages\"]\n",
-    "\n",
-    "\n",
-    "plt.fill_between(x, y2, color='#539ecd')\n",
-    "\n"
+    "y = my_data[\"Wages\"]\n",
+    "plt.fill_between(x, y, color='#539ecd')"
    ]
   },
   {
@@ -1725,6 +1723,7 @@
     }
    ],
    "source": [
+    "# Calculate the purchase_power \n",
     "# purchase_power = wages / wheat\n",
     "my_data[\"Purchase_Power\"] = my_data[\"Wages\"] / my_data[\"Wheat\"]\n",
     "\n",