Question 76

Which of the following is tautology?

Aa ∨ b → b ∧ c
Ba ∧ b → b ∨ c
Ca ∨ b → (b → c)
DNone of the above

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Correct answer: (B) a ∧ b → b ∨ c

Explanation

a ∧ b → b ∨ c is a tautology: whenever a ∧ b is true, b is true, so b ∨ c is true. The other implications can be false, for example when b and c are false.

From DSSSB TGT Computer Science Practice Set 4

This is question 76 of DSSSB TGT Computer Science Practice Set 4. See all questions of this paper with answers, or attempt the paper as a timed online test to get your score and all-India rank.