// class GasCost is saved as GasCost.java
public class GasCost {
    private double mpg; // miles per gallon
    private double dpg; // dollar per gallon

    // constructor
    public GasCost(double m, double d){
        mpg = m;
        dpg = d;
    }

    public double totalDollar(double miles) {
        double totalGallon;
        totalGallon = miles / mpg;
        return dpg * totalGallon;
    }
}

// class Main is saved as Main.java
public class Main {

    public static void main(String[] args) {
 		System.out.println("Hello, World!");

		// test GasCost
		GasCost gasCost = new GasCost(19.5, 2.29);
		double cost = gasCost.totalDollar(105);
		System.out.println("Cost of the trip is $" + cost);

    }
}