Which of the following propositions are so related that if one of them is true, the other has to be false, and vice versa?

1.All camels are herbivorous

2.Some camels are herbivorous

3.Some camels are not herbivorous

4.No camels are herbivorous

A1 & 4 only

B2 & 4 only ✓ Correct

C2 & 3 only

D1 & 2 only

Correct answer: (B) 2 & 4 only

Explanation

Statement 2 and Statement 4 flip truth value against each other, being exact contradictories.

Statement 2 is the particular affirmative I: Some camels are herbivorous.

Statement 4 is the universal negative E: No camels are herbivorous.

The relation demanded, one true forcing the other false and vice versa, defines contradiction.

On the square of opposition I and E occupy diagonally opposite corners as contradictories.

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