Intefaces doesn't provide implementation hence a interface cannot implement another interface.
Yes an Interface can inherit another Interface, for that matter an Interface can extend more than one Interface.
Not possible. A Class can extend only one class but can implement any number of Interfaces.
Static variables are class level variables where all objects of the class refer to the same variable. If one object changes the value then the change gets reflected in all the objects.
Static varaibles are class level variables and they can't be declared inside a method. If declared, the class will not compile.