using System;

​

public class Program

{

    static double addVAT(double netPrice)

    {

    const double VATRate =0.20;

        double VAT = netPrice *VATRate;

        double priceWithVAT = netPrice +VAT;

        return priceWithVAT;

    }

    public static void Main()

    {

        double priceNoVAT = 50.00; //double is used when you have a number with a decimal place 

        double sellingPrice = addVAT(priceNoVAT);

        Console.WriteLine("The Selling price is: " +sellingPrice);

    }

}