If the statement Some animals are birds is given as false, then which of the following statements could be immediately inferred to be true?

1.All animals are birds

2.No animals are birds

3.Some animals are not birds

4.All birds are animals

A2 only

B1 & 4 only

C3 only

D2 & 3 only ✓ Correct

Correct answer: (D) 2 & 3 only

Explanation

Statements 2 and 3 can both be inferred true from the false I proposition.

Some animals are birds is the I statement declared false.

Its contradictory E, No animals are birds, is therefore true, giving Statement 2.

The subaltern O of that true E, Some animals are not birds, is also true, giving Statement 3.

The A form is false and All birds are animals remains undetermined.

Want more like this? Create a free account to practise a full test, track your progress, and get spaced-repetition review.