Question

Some statements are given, followed by some conclusions. Consider the statements to be true even if they seem to be at variance from commonly known facts. Decide which of the given conclusions follow from the given statements.

Statements:
All buildings are rains.
All papers are buildings.
All dogs are papers.
Conclusions:
I. All dogs are rains.
II. Some papers are rains.
III. Some rains are buildings.
IV. Some rains are papers.

• A. Only conclusions I and II follow
• B. Only conclusions II and III follow
• C. Only conclusions I, II and III follow
• D. Only conclusions I, III and IV follow
• E. All the conclusions follow

Answer 1

The correct option is D Only conclusions I, III and IV follow

Clearly, III is the converse of the first premise and so it holds.
All papers are buildings, All buildings are rains.
Since both the premises are universal and affirmative, the conclusion must also be universal and affirmative and should not contain the middle term. So, it follows that `All papers are rains'. IV is the converse of this conclusion and so it holds.
All dogs are papers. All papers are buildings.
Clearly, it follows that 'All dogs are buildings'.
All dogs are buildings. All buildings are rains.
Clearly, it follows that 'All dogs are rains'. So, conclusion I follows.
Thus, I, III and IV follow from the given premises.