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Saturday, 31 October

JEE Main 2021 · MathsMultiple choiceSingle correctEasyConceptual

JEE Main 18 March 2021, Shift 2, Maths Q62

Question 62 of 90 in this shift, Maths question 2 of 30, Section A.

If P and Q are two statements, then which of the following compound statement is a tautology ?
  1. (1)((P⇒Q)∧∼Q)⇒P((P\Rightarrow Q)\wedge\sim Q)\Rightarrow P
  2. (2)((P⇒Q)∧∼Q)⇒Q((P\Rightarrow Q)\wedge\sim Q)\Rightarrow Q
  3. (3)((P⇒Q)∧∼Q)⇒∼P((P\Rightarrow Q)\wedge\sim Q)\Rightarrow\sim POfficial answer
  4. (4)((P⇒Q)∧∼Q)⇒(P∧Q)((P\Rightarrow Q)\wedge\sim Q)\Rightarrow(P\wedge Q)

Official answer

Option 3

NTA final key.

Topic
No close match in our taxonomy
Idea tested
No close match in our taxonomy

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.