diff --git a/rabbits-and-foxes-kmc-question.ipynb b/rabbits-and-foxes-kmc-question.ipynb
index 657efb4..dc06f6d 100644
--- a/rabbits-and-foxes-kmc-question.ipynb
+++ b/rabbits-and-foxes-kmc-question.ipynb
@@ -23,7 +23,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 4,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -79,13 +79,67 @@
     }
    },
    "outputs": [],
-   "source": []
+   "source": [
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "time = 0\n",
+    "rabbit  = 400\n",
+    "fox = 200\n",
+    "\n",
+    "times = [time]\n",
+    "rabbits = [rabbit]\n",
+    "foxes = [fox]\n",
+    "\n",
+    "end_time = 600\n",
+    "\n",
+    "k1 = 0.015 # birth rate of rabbits /day\n",
+    "k2 = 0.00004 # death rate of rabbits due to foxes /day\n",
+    "k3 = 0.0004 # birth rate of foxes due to rabbits /day\n",
+    "k4 = 0.04 # death rate of foxes /day\n",
+    "\n",
+    "while time < end_time:\n",
+    "    rate_rabbit_birth = k1 * rabbit\n",
+    "    rate_rabbit_death = k2 * rabbit * fox\n",
+    "    rate_fox_birth = k3 * rabbit * fox\n",
+    "    rate_fox_death = k4 * fox\n",
+    "\n",
+    "    rates = np.array([rate_rabbit_birth, rate_rabbit_death, rate_fox_birth, rate_fox_death])\n",
+    "    cumulative_rates = rates\n",
+    "    total_rate = cumulative_rates[-1]\n",
+    "\n",
+    "    u = np.random.uniform(0,1)\n",
+    "    break # exit loop while its incomplete\n",
+    "    "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "for n in range(10):\n",
+    "    u = np.random.uniform(0,1)\n",
+    "    for i, cum_rate in enumerate(cumulative_rates):\n",
+    "        if cum_rate/total_rate > u:\n",
+    "            event = i\n",
+    "            break\n",
+    "            print(u, event )\n",
+    "            "
+   ]
   }
  ],
  "metadata": {
   "anaconda-cloud": {},
   "kernelspec": {
-   "display_name": "5137",
+   "display_name": "jb",
    "language": "python",
    "name": "python3"
   },
@@ -99,7 +153,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.11.5"
+   "version": "3.12.11"
   }
  },
  "nbformat": 4,