Negation of “Ram is in Class $X$ or Rashmi is in Class $XII$” is
Ram is not in class $X$ but Ram is in class $XII$
Ram is not in class $X$ but Rashmi is not in class $XII$
Either Ram is not in class $X$ or Ram is not in class $XII$
None of these
The statement $p → (p \leftrightarrow q)$ is logically equivalent to :-
Contrapositive of the statement “If two numbers are not equal, then their squares are not equals” is
$(p \wedge \, \sim q)\, \wedge \,( \sim p \vee q)$ is :-
$\left(p^{\wedge} r\right) \Leftrightarrow\left(p^{\wedge}(\sim q)\right)$ is equivalent to $(\sim p)$ when $r$ is.
Which one of the following is a tautology ?