Question

In each of the questions below, there are three statements followed by four conclusions numbered I, II, III and IV. You have to take the given statements to be true even if they seem to be at variance from commonly known facts. Read all the conclusions and then decide which of the given conclusions logically follows from the given statements, disregarding commonly known facts.

Statements
Some chairs are buildings.
All buildings are vehicles.
Some vehicles are trucks.

Conclusions
I. Some chairs are trucks.
II. Some chairs are vehicles.
III. Some vehicles are buildings.
IV. No truck is a chair.

• A. None of the above
• B. II and III only
• C. Either only I or II and III and IV
• D. Either only I or IV and II and III
• E. All of the above

Answer 1

The correct option is D Either only I or IV and II and III

The first and third premises are particular affirmative (I- type).
The second premise is universal affirmative (A-type).
Some chairs are buildings.
All buildings are vehicles.
We know that,
$I+A\Rightarrow I$-type conclusion
Thus, our derived conclusion would be, some chairs are vehicles.
This is the conclusion II.
Conclusion III is the converse of the second premise.
Conclusions I and IV form a complementary pair. Therefore, either conclusion I or IV follows.