GasMileage.java

import java.util.Scanner;

public class GasMileage {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        System.out.print("Enter the distance in miles: ");
        double distance = scan.nextDouble();
        while (distance < 0) {
            System.out.print("Negative distance is not allowed. Enter again: ");
            distance = scan.nextDouble();
            System.out.println();
        }

        System.out.print("Enter the gas in gallons: ");
        double gallons = scan.nextDouble();
        while (gallons < 0) {
            System.out.print("Negative gallons is not allowed. Enter again: ");
            gallons = scan.nextDouble();
            System.out.println();
        }

        System.out.printf("The number of gallons of gas consumed by the car is %,.2f miles per gallon", distance/gallons);

    }

}