public static void main(String[] args) {
    Double d=new Int();

    d.test(10);

    d.add(1,2,3);
}

void test(double d) {
    System.out.println("Value of D:"+ d);
}

    public void add(double a, double b, double c){
        double sum = a+b+c;
        System.out.println("sum Double:"+ sum);

    }

void test(int i) {
    System.out.println("i:"+ i);
}

public void add(int a, int b, int c){
        int sum = a+b+c;
        System.out.println("sum Int:"+ sum);
    }