Statement: Either P marries Q or X marries Y. Among the options below, the logical NEGATION of the above statement is: A. P does not marry Q and X marries Y. B. Neither P marries Q nor X marries Y. C. P does not marry Q and X does not marry Y. D. P marries Q and X marries Y.

GATE 2021 · General Aptitude · Family Relationship · medium

Answer: B. Neither P marries Q nor X marries Y.

  1. Formalize the given statement: Let A = 'P marries Q', B = 'X marries Y'. The given statement is A OR B.
  2. Apply De Morgan's law to negate: NOT(A OR B) = (NOT A) AND (NOT B) = 'P does not marry Q' AND 'X does not marry Y'.
  3. Match to option: Option B states 'Neither P marries Q nor X marries Y', which means 'P does not marry Q AND X does not marry Y'. This exactly matches NOT(A OR B).