Which of the following propositions are so related that they cannot both be true, although they both may be false?

1.All football players are rich persons

2.No football players are rich persons

3.Some football players are rich persons

4.Some football players are not rich persons

A1 & 2 only ✓ Correct

B1 & 4 only

C3 & 4 only

D2 & 3 only

Correct answer: (A) 1 & 2 only

Explanation

Statement 1 and Statement 2 are the pair that cannot both be true yet can both be false.

That description defines the relation of contrariety.

Statement 1 is the universal affirmative A, All football players are rich.

Statement 2 is the universal negative E, No football players are rich.

Two universals of opposite quality are contraries on the square of opposition.

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