%%

Let r $$\in$$ {p, q, $$\sim$$p, $$\sim$$q} be such that the logical statement r $$\vee$$ ($$\sim$$p) $$\Rightarrow$$ (p $$\wedge$$ q) $$\vee$$ r is a tautology. Then r is equal to :

JEE · Math · previous-year question

  1. A.p
  2. B.q
  3. C.$$\sim$$pcorrect
  4. D.$$\sim$$q

Answer

C. $$\sim$$p

Explanation

Clearly r must be equal to $$\sim$$ p $$\because$$ $$\sim$$ p $$\vee$$ $$\sim$$ p = $$\sim$$ p and (p $$\wedge$$ q) $$\vee$$ $$\sim$$ p = p $$\therefore$$ $$\sim$$ p $$\Rightarrow$$ p = tautology.

Practice more JEE questions

Answer thousands more real JEE previous-year questions free, get graded instantly, and climb the global ranked leaderboard.

Practice JEE free →

More JEE Math questions