//Driver
    package asdfghjkl;

    import java.util.ArrayList;

    public class Driver
    {
        public static ArrayList<SaleCalculator> revenueList = new ArrayList<SaleCalculator>();
        public static float totalRevenue = 0.0f;
        public static void main(String[] args)
        {
            ALSalesCalculator alabamaSales = new ALSalesCalculator();
            revenueList.add(alabamaSales);
            AKSalesCalculator alaskaSales = new AKSalesCalculator();
            revenueList.add(alaskaSales);

            for (int i = 0; i < revenueList.size(); i++)
            {
                revenueList.get(i).Calculate();
                totalRevenue += revenueList.get(i).revenue;
            }
            System.out.println("Total revenue: $" + (totalRevenue));
        }

    }

//Sale Calculator
package asdfghjkl;

public abstract class SaleCalculator
{
    float salesTax;
    float unitPrice = 50.0f;
    float unitsSold = 10000.0f;
    String stateName;
    public float revenue;

    public void Calculate()
    {
        revenue = (int)unitsSold * (unitPrice + (salesTax * unitPrice));
        System.out.println("Revenue in " + stateName + ": $" + revenue);
    }
}

//State specific calculators
    package asdfghjkl;

    public class AKSalesCalculator extends SaleCalculator
    {
        public AKSalesCalculator()
        {
            salesTax = 0.04f;
            stateName = "Alaska";
        }
    }


package asdfghjkl;

public class ALSalesCalculator extends SaleCalculator
{
    public ALSalesCalculator()
    {
        salesTax = 0.04f;
        stateName = "Alabama";
    }
}