Which of the following is not true for any two statements and ?
Explanation for correct option
A tautology is a compound statement that is always true.
Signs of tautology:
Symbol | Meaning |
Not | |
And | |
Or | |
Implies or If-then |
Make truth table to check the relation
From the table it clear that is is
Explanation for incorrect option
Option (A)
Make truth table to check the relation
Thus the relation is true.
Option (C)
Since the results are false. So it is a contradiction.
For option (D)
Since the results are true. So is a tautology
Hence option (B) is the correct option.