Business layer for a c#.net application

C#.net You need to create a business layer for an application to rent out computers. The app. is supposed to work with any db and any GUI as the customer wish to use. You also need to create a simple consoleapp. to use to be able to test that the usercases work properly. ## Deliverables You should implement the usercases below? plus testcases belonging to them. The testcases should be done from a simple consoleapplication **Specification:? **The system this is used in are being adapted for several different customers which all have different desires on how the? data should be stored and which type of GUI to be used. You should implement a small part of the business logic with testcases which verifies that the logic works as follows: * There are two categorys of computers, laptop and workstation? ...more categorys can be added * One rent out is defined by a unique booking number * One rent out is one computer **Usercase to implement:** **1.** The following should be registred when a computer is being handed out to a customer: * booking number * categoy of the computer being handed out * date and time * how many hours it has been used for **2.** The following should be registred when a customer returns a computer: * booking number * date and time * how many hours it has been used for After this registration has been made the system should calculate the prise for the customer to pay using? the rent out formulas below. **Rent out formulas: **Two different formulas, one for each computer category. The formulas take two parameters which can differ - *dayRent* and *pricePerHour * * laptop - Price = dayRent * days * 1,1 * pricePerHour * workstation - Price = dayRent * days