Question

Two statements are given, followed by three conclusions numbered I, II and III. Assuming the statements to be true, even if they seem to be at variance with commonly known facts, decide which of the conclusions logically and definitely follow(s) from the statements.

Statements:

All donkeys are horses.

No cow is a horse.

Conclusions:

I. Some cows are donkeys

II. Some horses are donkeys.

III. No donkeys is a cow.

• A. Both conclusions II and III follow
• B. Only conclusion II follows
• C. Only conclusion III follows
• D. Either conclusion II or III follows

Answer 1

Answer:

A. Both conclusions II and III follow

Solution: The least possible Venn diagram for the given statements is as follows,

Conclusions:

I. Some cows are donkeys → False (All donkeys are horses and no cow is a horse, imply that no cows are donkeys)

II. Some horses are donkeys → True (All donkeys are horses imply that some horses are donkeys)

III. No donkeys is a cow → True (All donkeys are horses and no cow is a horse, imply that no donkeys are cow)

Hence, the correct answer is Both conclusions II and III follow.