The problem describes a scenario where a customer orders a product with a listed price of $100, but is charged $110 at checkout due to a hidden delivery cost of $10. This cost is not disclosed until the checkout stage. Below is a Python function that calculates the total cost including the hidden delivery fee:

def calculate_total_price(product_price, delivery_cost=10):
    """
    Calculate the total price including a fixed hidden delivery cost.
    Args:
        product_price (float): The listed price of the product.
        delivery_cost (float, optional): The hidden delivery cost. Defaults to $10.
    Returns:
        float: Total price including delivery cost.
    """
    return product_price + delivery_cost
product_price = 100.0
total_price = calculate_total_price(product_price)
print(f"Total price: ${total_price:.2f}")  # Output: Total price: $110.00

Explanation:

1. Function Definition: The function calculate_total_price takes two parameters:

   • product_price: The base price of the product (e.g., $100).
   • delivery_cost: The hidden delivery fee (defaults to $10 if not specified).

2. Calculation: The total price is computed by adding the product price and the delivery cost:

   return product_price + delivery_cost

3. Example: For a product priced at $100, the function returns $110, reflecting the hidden $10 delivery fee.

Key Points:

• Hidden Cost: The delivery cost is not displayed until checkout, encouraging initial purchases without upfront transparency.
• Customization: The delivery_cost parameter allows flexibility to adjust fees (e.g., based on location, weight, or promotions).
• Output: The total price is returned as a float, formatted to two decimal places for currency consistency.

This solution models the hidden delivery cost scenario while providing a reusable function for pricing calculations.