JEE PYQ: Mathematical Reasoning Question 4
Question 4 - 2021 (18 Mar Shift 2)
If $P$ and $Q$ are two statements, then which of the following compound statement is a tautology?
(1) $((P \Rightarrow Q) \wedge \sim Q) \Rightarrow Q$
(2) $((P \Rightarrow Q) \wedge \sim Q) \Rightarrow \sim P$
(3) $((P \Rightarrow Q) \wedge \sim Q) \Rightarrow P$
(4) $((P \Rightarrow Q) \wedge \sim Q) \Rightarrow (P \wedge Q)$
Type: MCQ
Show Answer
Answer: (2)
Solution
$((P \Rightarrow Q) \wedge \sim Q) \equiv (\sim P \vee Q) \wedge \sim Q \equiv \sim P \wedge \sim Q$
(B) $(\sim P \wedge \sim Q) \to \sim P \equiv (P \vee Q) \vee \sim P \Rightarrow$ Tautology
BETA
