Which of the following statements are logically equivalent? Choose the correct answer from the options given below.

1.All cats are carnivorous animals.

2.All non-carnivorous animals are non-cats.

3.No cats are non-carnivorous animals.

4.Some carnivorous animals are cats.

A1, 2, 3 only ✓ Correct

B2, 3, 4 only

C1, 3, 4 only

D3, 4 only

Correct answer: (A) 1, 2, 3 only

Explanation

Three propositions are equivalent: "All cats are carnivorous animals" with its obverse and its contrapositive.

Statement 1 is the universal affirmative A.

Statement 3, "No cats are non-carnivorous animals", is the obverse of A and keeps its meaning.

Statement 2, "All non-carnivorous animals are non-cats", is the contrapositive of A, also valid and equivalent.

Statement 4, a converse by limitation, does not carry the full force of the universal and is left out.

Obversion and contraposition preserving truth make Statements 1, 2 and 3 logically equivalent.

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