in java

Question 6 (30 points) Write an interface iMath which has 2 methods add() and subtract(). Each takes in 2 integers, and returns an integer. Next write an abstract class Calculator which implements the interface iMath. It should implement the methods of the interface, and have 2 additional abstract methods multiply() and divide(), multiply() and divide() should take in 2 doubles each, and should both return a double. Finally, implement a concrete class Texasinstrument which inherits from Calculator, and implements the two abstract classes it inherited