Statements:
A. No lighthouses are firehouses.
B. All mansions are lighthouses.
Conclusions:
I. No firehouses are mansions.
II. All mansions are firehouses.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Only conclusion I follows
A conclusion follows only if it is true in every diagram that fits the statements.
“All mansions are lighthouses”: the mansions circle lies inside the lighthouses circle.
“No lighthouses are firehouses”: the firehouses circle does not touch the lighthouses circle.
Conclusion I (No firehouses are mansions) follows: every mansion is inside the lighthouses circle, and nothing in that circle is a firehouse.
Conclusion II (All mansions are firehouses) does not follow: no mansion can be a firehouse at all, so this is false in every diagram.