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GATE 2021 CY – Question 6

General Aptitude · Analytical Aptitude: Logical Reasoning and Deduction · 2 marks · Multiple choice

Statement: Either P marries Q or X marries Y Among the options below, the logical NEGATION of the above statement is:

  1. P does not marry Q and X marries Y.
  2. Neither P marries Q nor X marries Y.
  3. X does not marry Y and P marries Q.
  4. P marries Q and X marries Y.

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Show answer and explanation

Correct answer: (B) Neither P marries Q nor X marries Y.

Explanation

Write the two propositions as A and B. De Morgan’s law gives ¬(A∨B)=¬A∧¬B. Both marriages must therefore fail for the original disjunction to be false. This is **neither P marries Q nor X marries Y, B**.