Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If P and Q are two statements, then which of the following compound statement is a tautology?
MathematicsMathematical ReasoningJEE MainJEE Main 2021 (18 Mar Shift 2)
Options:
  • A ((PQ)~Q)Q
  • B ((PQ)~Q)~P
  • C ((PQ)~Q)P
  • D ((PQ)~Q)(PQ)
Solution:
2096 Upvotes Verified Answer
The correct answer is: ((PQ)~Q)~P

LHS of all the options are same i.e. ((PQ)~Q)

(~PQ)~Q

(~P~Q)(Q~Q)

~P~Q

(A) (~P~Q)Q

~(~P~Q)Q

(PQ)Q tautology

(B) (~P~Q)~P

~(~P~Q)~P

(PQ)~P

(C) (~P~Q)P

(PQ)P Tautology

(D) (~P~Q)(PQ)

(PQ)(PQ) Tautology

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.