diff --git a/lab-python-data-structures b/lab-python-data-structures
new file mode 160000
index 00000000..250c5f8d
--- /dev/null
+++ b/lab-python-data-structures
@@ -0,0 +1 @@
+Subproject commit 250c5f8d9b7bf5130d6b5f131781834ad18590a4
diff --git a/lab-python-data-structures.ipynb b/lab-python-data-structures.ipynb
index 5b3ce9e0..c8aaee6a 100644
--- a/lab-python-data-structures.ipynb
+++ b/lab-python-data-structures.ipynb
@@ -50,11 +50,83 @@
     "\n",
     "Solve the exercise by implementing the steps using the Python concepts of lists, dictionaries, sets, and basic input/output operations. "
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "\n",
+    "# answers:\n",
+    "\n",
+    "print(\"\\nInventory\")\n",
+    "\n",
+    "# 1. Define a list called product:\n",
+    "products = [\"t-shirt\", \"mug\", \"hat\", \"book\", \"keychain\"]\n",
+    "\n",
+    "# 2. Create an empty inventory dictionary:\n",
+    "inventory = {}\n",
+    "\n",
+    "# 3. Ask the user to enter the quantity available for each product\n",
+    "\n",
+    "for product in products:\n",
+    "    quantity = int(input(f\"Enter the available quantity for '{product}': \"))\n",
+    "    inventory[product] = quantity\n",
+    "    print(f\"{product}: {inventory[product]}\")\n",
+    "# 4. Create an empty set for customer orders\n",
+    "customer_orders = set()\n",
+    "print(customer_orders)\n",
+    "\n",
+    "# 5. Ask the user to input three products the customer wants to order:\n",
+    "\n",
+    "for i in range(1, 4):\n",
+    "    product_name = input(f\"Enter the name of product #{i}: \").strip().lower()     \n",
+    "    #F-strings are string literals prefixed with 'f' or 'F' that contain expressions inside curly braces {}.\n",
+    "    # The user has to type a product from the list (t-shirt, mug, hat, book, keychain)\n",
+    "    if product_name in products:\n",
+    "        customer_orders.add(product_name)\n",
+    "    else:\n",
+    "        print(\"Invalid product, this item will be ignored.\")\n",
+    "\n",
+    "# 6. Print the products in the customer_orders set:\n",
+    "print(\"Products in the customer's order (set):\")       \n",
+    "for item in customer_orders:\n",
+    "    print(\"- \", item)\n",
+    "\n",
+    "# 7. Calculate order statistics:\n",
+    "total_products_ordered = len(customer_orders)\n",
+    "\n",
+    "# Percentage of products ordered compared to the total number of products:\n",
+    "percentage_ordered = (total_products_ordered / len(products)) * 100\n",
+    "\n",
+    "order_status = (total_products_ordered, percentage_ordered)\n",
+    "\n",
+    "# 8. Print the order statistics:\n",
+    "print(\"\\nOrder Statistics:\")        #order statut : a tuple or list\n",
+    "print(f\"Total Products Ordered: {order_status[0]}\")\n",
+    "print(f\"Percentage of Products Ordered: {order_status[1]:.2f}%\")  #order_status[1]: access to the second element\n",
+    "# : starts the format specification.\n",
+    "# .2f means:\n",
+    "#    f → format as a floating-point number,\n",
+    "#   .2 → keep 2 digits after the decimal point.\n",
+    "\n",
+    "# 9. Update the inventory by subtracting 1 from the quantity of each ordered product:\n",
+    "for ordered_product in customer_orders:\n",
+    "    if inventory[ordered_product] > 0:\n",
+    "        inventory[ordered_product] -= 1\n",
+    "\n",
+    "# 10. Print the updated inventory:\n",
+    "print(\"\\nUpdated Inventory\")\n",
+    "for product in products:\n",
+    "    print(f\"{product}: {inventory[product]}\")\n",
+    "\n"
+   ]
   }
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": "base",
    "language": "python",
    "name": "python3"
   },
@@ -68,7 +140,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.13"
+   "version": "3.13.5"
   }
  },
  "nbformat": 4,