Question

In each of the following questions, two statements are given followed by two conclusions, I and II. You have to consider the statements to be true, even if they seem to be at variance from commonly known facts. You have to decide which of the given conclusions if any, follows from the given statements.

Statements
All frogs are tortoises.
No tortoise is a crocodile.

Conclusions
I. No crocodile is a frog.
II. No frog is a crocodile.

• A. Only I follows
• B. Only II follows
• C. Both I and II follow
• D. Neither I nor II follows
• E. None of the above

Answer 1

The correct option is C Both I and II follow

The first premise is universal affirmative (A-type).
The second premise is universal negative (E-type).
All frogs are tortoises
No tortoise is a crocodile
$A+E\Rightarrow E$-type of conclusion
"No frog is a crocodile".
This is conclusion II.
Conclusion I is the converse of this conclusion.