Question

"All cars are books" and Some books are files". If both these statements are true, then which of the following statements is definitely true?

• A. Some files are cars.
• B. No car is a file.
• C. All books are cars
• D. None of these

Answer 1

The correct option is D None of these

The first premise is universal affirmative (A-type)
The second premise is particular affirmative (I -type).
All cars are books.
Some books are files.
$A+I\Rightarrow$ No conclusion
Valid conclusions
I. Some cars are books.
II. Some books are cars.
III. Some files are books.
Conclusions (1) and (2) form a complementary pair. Therefore, either (1) or (2) follows.