Question

Consider tables R and S below How many tuples are in the natural join of R and S ? B) 4 c) 5 OD) 6 E) 7

Answer 1

Natural join acts on the matching columns of the tables where the values are same in both the tables and returns those tuples.

Here for tables R & S the matching column is B.

Therefore the natural join of R & S has 5 tuples.

ANSWER: C

In the given Inheritance problem,

Class A has a public variable y and a private variable x

Class B has a private variable z, and it inherits only the public variable y from its parent class A.

The private variable x cannot be inherited into B as it is private to Class A.

Now Class B has a private variable z, and the public variable y

Now lets say there's a class Z such that

public Class Z {

//some code

B b = new B();

//some code

}

Now in the class Z where an object b of Class b is created, we cannot directly initialize any of the private variables as they are only accessible through getters and can be set using the setters.

Therefore we can only initialize the public variable y.

ANSWER: B

All the best!