Difficulty: Easy
Correct Answer: Only IV follows
Explanation:
Introduction / Context:This syllogism checks whether you can combine a universal negative with a universal affirmative to deduce a new universal negative about a related class. The “some” statements here cannot be chained unless overlap is guaranteed.
Given Data / Assumptions:
Concept / Approach:If a set A is disjoint from set B, then A is disjoint from any subset of B. Since flowers are a subset of jungles and roads are disjoint from jungles, roads must also be disjoint from flowers. Particular statements (“some”) cannot be chained without additional inclusion relations.
Step-by-Step Solution:
I. “Some trains are flowers” — not supported; nothing connects trains to flowers except that some trains are roads and roads are disjoint from jungles (and thus from flowers). This blocks, rather than supports, overlap.II. “Some trains are jungles” — not supported; the known train-road overlap lies outside jungles.III. “Some flowers are trains” — not supported; flowers ⊆ jungles, and we only know some trains are roads, which are disjoint from jungles.IV. “No road is flower” — follows, because flowers ⊆ jungles and roads ∩ jungles = ∅, hence roads ∩ flowers = ∅.Verification / Alternative check:Model roads entirely outside jungles while placing all flowers inside jungles. Then I–III fail but IV is necessarily true.
Why Other Options Are Wrong:
Common Pitfalls:Attempting to chain “some” statements; ignoring that a universal disjointness blocks any overlap claims.
Final Answer:Only IV follows
Discussion & Comments