$1.$ Create a console$-$based program whose Main$()$ method prompts the user to enter the sale amounts of two products. Within the class, create the following methods:

a$.$ CalculateTotalSales$()$ calculates the total sales of the two products and returns the result to the calling method.

b$.$ CalculateTax$()$ takes a literal tax rate $($let$\text{'}$s say $15\%)$ as an input, calculates the tax on the total sale amount, and returns the result.

c$.$ calculateGrandTotal$()$: This method computes and outputs the total amount the user must pay, which is the total plus the tax.

The program's output should display the product sales, total, tax, and grand total amount in a well$-$presented report.

$(6$ Marks$)$

$2.$ Create a GUI application that contains the methods described in Exercises $($a$)$ to $($c$).$ When the user enters the sale amounts in textboxes and clicks a button, it display the report in a label. must be in c#