Difficulty: Easy
Correct Answer: None follows
Explanation:
Introduction / Context:This problem is a classic illustration that chaining several “some” statements does not justify concluding overlap among the first and last sets. Each “some” could refer to disjoint subgroups that never meet.
Given Data / Assumptions:
Concept / Approach:With only particular affirmatives, intersections need not align. You cannot infer transitive overlap for “some.” Likewise, universal statements like “All horses are rabbits” cannot be derived from a single “some.”
Step-by-Step Solution:
Construct a countermodel: Let T∩L contain element a; L∩R contain element b (with b ≠ a); R∩H contain element c (c ≠ b, a). All premises hold. However, T∩H may be empty ⇒ Conclusion I fails.R∩T can be empty ⇒ Conclusion II fails.H∩L can be empty ⇒ Conclusion III fails.Only “some rabbits are horses” was given; “All horses are rabbits” is much stronger and not implied ⇒ Conclusion IV fails.Verification / Alternative check:The single countermodel suffices to show none of the four conclusions is logically necessary given the premises.
Why Other Options Are Wrong:
Common Pitfalls:Illegally chaining “some” statements; confusing “some” with “all.”
Final Answer:None follows
Discussion & Comments