This code is correct or not?

Question

https://code.sololearn.com/cOBqULsZJ3GD/?ref=app

Answer 1

also in main() call start()
and print result of getSum()

Answer 2

Sorry i cant understand let you explain this pls

Answer 3

public static void main(String[] args)
{
AddingTwoNumbers ad = new AddingTwoNumbers();
ad.start(); //@zemiak telling //add this at line no:45
System.out.println(ad.getSum());//print returned value
ad = null;

} //@Martin telling //remove '}' from line no:40, amd add this at line 48
}

//observe changes..