JEE Main 2023 · 24 Jan · Shift 1 · Paper-1(B.E./B. Tech.)

JEE Main 2023 Mathematics question on Mathematical Reasoning

The compound statement (∼(P∧Q))∨((∼P)∧Q)⇒((∼P)∧(∼Q))(\sim(P \wedge Q)) \vee ((\sim P) \wedge Q) \Rightarrow ((\sim P) \wedge (\sim Q)) is equivalent to
  1. A.
    (∼Q)∨P(\sim Q) \vee P
  2. B.
    ((∼P)∨Q)∧((∼Q)∨P)((\sim P) \vee Q) \wedge ((\sim Q) \vee P)
  3. C.
    (∼P)∨Q(\sim P) \vee Q
  4. D.
    ((∼P)∨Q)∧(∼Q)((\sim P) \vee Q) \wedge (\sim Q)
Show answer and solution

Correct option: B

Solution

The antecedent simplifies: ~(P∧Q) ∨ (~P∧Q) = (~P∨~Q) ∨ (~P∧Q) = ~P ∨ (~Q∧(P∨1)) = ~P ∨ ~Q (since ~P∨~Q already covers the ~P∧Q case, so the whole antecedent is just ~P∨~Q, i.e., ~(P∧Q)).

The implication ~(P∧Q) ⇒ (~P∧~Q) is equivalent to (P∧Q) ∨ (~P∧~Q), which means P↔Q (both same truth value).

Now check option 2: (~P∨Q) ∧ (~Q∨P) = (P→Q) ∧ (Q→P) = P↔Q.

This matches exactly, so option 2 is equivalent to the given compound statement.

[JEE Main 2023 · 24 Jan · Shift 1 · Paper-1(B.E./B. Tech.)]

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