JEE Main · 2021 · 17 Mar 2021 · Shift 2 · Mathematical Reasoning *

WhatsApp Email
If the Boolean expression is a tautology, then and are respectively by:
  1. (A)→ , →✓ Correct
  2. (B)
  3. (C)
  4. (D)

Answer: (A)

Solution

Take both connectives to be the implication, giving . If is true, then and are both true, so is true and the whole statement is true; if is false, an implication with a false antecedent is true. The statement holds in all four rows of the truth table, so it is a tautology.
No other pairing works: and are both false when is false, and is false when is true and is false.
So and are both the implication .

JEE Main · 2021 · 17 Mar 2021 · Shift 2 · Single correct option

More JEE Main questions on Mathematical Reasoning *

  1. Among the statements
    (S1): is a tautology
    (S2): is a contradiction
    JEE Main 2023View solution →
  2. Negation of is
    JEE Main 2023View solution →
  3. Statement is logically equivalent to
    JEE Main 2023View solution →
  4. The negation of is equivalent to
    JEE Main 2023View solution →
  5. The statement is equivalent to
    JEE Main 2023View solution →
  6. The negation of the statement is
    JEE Main 2023View solution →