UST Global interview questions.

1. What is the main difference between xpath and css selector.
2. If there 4 frames in the application . How will you get the 4rth frame ID.
3. If there is a ok button. How many ways you can click.
4. What is the difference between try-catch block and throws clause.
5. If there is a abstract class A with methods M1,M2, M3.  And M1 and M2 are abstract methods and M3 is not abstract. Class B extends A. For M1 and M2 we get the implementation in next year. How will you use M3 in base class.
6. If there is a class A extends Class B.
If we create a reference of A and object of B , we can call only the method from Class A.
If same methods are present in class A and class B.
For the same scenario we can call the common methods present in both the classes and methods present in A why...????
7.  A a1 = new B(); and B b1 = new B();
How the method call will happen at run time and compile time in both the cases..
8. What is spin and re spin in agile and which phase the demo will show to the customer.
Can anyone provide the answer for 5,6,7 .