Which of the following statements are so related that if one of them is false, the other must be true, even though both of them can be true?

1.Some cars are e-vehicles

2.Some cars are not e-vehicles

3.No cars are e-vehicles

4.All cars are e-vehicles

A1, 2 ✓ Correct

B2, 3

C1, 3

D3, 4

Correct answer: (A) 1, 2

Explanation

Statement 1 and Statement 2 are sub-contraries and are the required pair.

The relation asked for allows both to be true but forbids both being false.

Statement 1 is the particular affirmative, Statement 2 the particular negative.

On the square of opposition the two particular propositions are sub-contraries.

They can hold together, yet at least one must be true, so both cannot be false.

This is exactly the sub-contrary relation the question describes.

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