diff --git a/lab-python-error-handling.ipynb b/lab-python-error-handling.ipynb
index f4c6ef6..7a9c403 100644
--- a/lab-python-error-handling.ipynb
+++ b/lab-python-error-handling.ipynb
@@ -72,6 +72,262 @@
     "\n",
     "4. Test your code by running the program and deliberately entering invalid quantities and product names. Make sure the error handling mechanism works as expected.\n"
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "f4ef1ac0-1b48-46a0-a6f2-d1a6402829fc",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "products = ['t-shirt', 'mug', 'hat', 'book', 'keychain']\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "e3a34eb1-f139-4b00-aafd-ce720e527f2c",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def initialize_inventory(products):\n",
+    "    inventory = {}\n",
+    "    for product in products:\n",
+    "        valid_input = False\n",
+    "        while not valid_input:\n",
+    "            try:\n",
+    "                quantity = int(input(f\"Enter the quantity of {product}s available: \"))\n",
+    "                if quantity >= 0:\n",
+    "                    inventory[product] = quantity\n",
+    "                    valid_input = True\n",
+    "                else:\n",
+    "                    print(\"Quantity cannot be negative. Please enter a valid quantity.\")\n",
+    "            except ValueError:\n",
+    "                print(\"Invalid input. Please enter a valid quantity.\")\n",
+    "    return inventory"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "f828ae3b-594e-4a06-9985-549f16d57577",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#2.\n",
+    "def calculate_total_price(customer_orders):\n",
+    "    total_price = 0\n",
+    "\n",
+    "    for product in customer_orders:\n",
+    "        valid_input = False\n",
+    "        while not valid_input:\n",
+    "            try:\n",
+    "                price = float(input(f\"Enter the price for {product}: \"))\n",
+    "                if price >= 0:\n",
+    "                    total_price += price\n",
+    "                    valid_input = True\n",
+    "                else:\n",
+    "                    print(\"Price cannot be negative. Please enter a valid price.\")\n",
+    "            except ValueError:\n",
+    "                print(\"Invalid input. Please enter a valid price.\")\n",
+    "\n",
+    "    return total_price\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "362fc934-4d72-4dea-8129-a4cf5920958e",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#3.\n",
+    "def get_customer_orders(inventory):\n",
+    "    customer_orders = set()\n",
+    "\n",
+    "    # Number of orders\n",
+    "    valid_input = False\n",
+    "    while not valid_input:\n",
+    "        try:\n",
+    "            number_orders = int(input(\"Enter the number of customer orders: \"))\n",
+    "            if number_orders > 0:\n",
+    "                valid_input = True\n",
+    "            else:\n",
+    "                print(\"Number of orders must be greater than zero.\")\n",
+    "        except ValueError:\n",
+    "            print(\"Invalid input. Please enter a valid number.\")\n",
+    "\n",
+    "    # Product names\n",
+    "    for _ in range(number_orders):\n",
+    "        valid_input = False\n",
+    "        while not valid_input:\n",
+    "            product = input(\"Enter the name of a product: \").lower()\n",
+    "\n",
+    "            if product in inventory and inventory[product] > 0:\n",
+    "                customer_orders.add(product)\n",
+    "                valid_input = True\n",
+    "            elif product not in inventory:\n",
+    "                print(\"Product not found in inventory.\")\n",
+    "            else:\n",
+    "                print(\"Product out of stock.\")\n",
+    "\n",
+    "    return customer_orders"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "3d8423bf-07a5-4940-8157-f3eb31f6f3ec",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#4."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "098eaae3-227b-4400-9aea-96c97c0ae012",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdin",
+     "output_type": "stream",
+     "text": [
+      "Enter the quantity of t-shirts available:  j\n"
+     ]
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Invalid input. Please enter a valid quantity.\n"
+     ]
+    },
+    {
+     "name": "stdin",
+     "output_type": "stream",
+     "text": [
+      "Enter the quantity of t-shirts available:  4\n",
+      "Enter the quantity of mugs available:  0\n",
+      "Enter the quantity of hats available:  1\n",
+      "Enter the quantity of books available:  r\n"
+     ]
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Invalid input. Please enter a valid quantity.\n"
+     ]
+    },
+    {
+     "name": "stdin",
+     "output_type": "stream",
+     "text": [
+      "Enter the quantity of books available:  5\n",
+      "Enter the quantity of keychains available:  6\n"
+     ]
+    }
+   ],
+   "source": [
+    "inventory = initialize_inventory(products)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "id": "a26736ec-2bee-45f2-a8cd-068d3dc29529",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdin",
+     "output_type": "stream",
+     "text": [
+      "Enter the number of customer orders:  2\n",
+      "Enter the name of a product:  6\n"
+     ]
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Product not found in inventory.\n"
+     ]
+    },
+    {
+     "name": "stdin",
+     "output_type": "stream",
+     "text": [
+      "Enter the name of a product:  mug\n"
+     ]
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Product out of stock.\n"
+     ]
+    },
+    {
+     "name": "stdin",
+     "output_type": "stream",
+     "text": [
+      "Enter the name of a product:  book\n",
+      "Enter the name of a product:  hat\n"
+     ]
+    }
+   ],
+   "source": [
+    "customer_orders = get_customer_orders(inventory)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "id": "a3c6c385-03f5-4cea-9143-74c7012d72df",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdin",
+     "output_type": "stream",
+     "text": [
+      "Enter the price for book:  10\n",
+      "Enter the price for hat:  5\n"
+     ]
+    }
+   ],
+   "source": [
+    "total_price = calculate_total_price(customer_orders)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "id": "a76e99f3-eafe-44e5-896c-64eec0e4119f",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Customer orders: {'book', 'hat'}\n",
+      "Total price: 15.0\n"
+     ]
+    }
+   ],
+   "source": [
+    "print(\"Customer orders:\", customer_orders)\n",
+    "print(\"Total price:\", total_price)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "c7da5782-4a97-4e53-8ad8-1ad689de1420",
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {
@@ -90,7 +346,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.13"
+   "version": "3.13.5"
   }
  },
  "nbformat": 4,