contrapositive

'When the teacher is in the room, all students stand silently.' If the above statement is true, which one of the following statements is not necessarily true?

'When it is raining, peacocks dance.' Based only on this sentence, which one of the following options is necessarily true?

The statement $(\neg p) \Rightarrow(\neg q)$ is logically equivalent to which of the statements below? I. $\quad p \Rightarrow q$ II. $q \Rightarrow p$ III. $(\neg q) \vee p$ IV. $...

Consider the following two statements. $$S1:$$ If a candidate is known to be corrupt, then he will not be elected $$S2:$$ If a candidate is kind, he will be elected Which one of th...

Consider the following statements: P: Good mobile phones are not cheap Q: Cheap mobile phones are not good L: P implies Q M: Q implies P N: P is equivalent to Q Which of the follow...