Introduction / Context:
Despite the odd wording, treat each term as a set label. We must determine which conclusions necessarily follow from the premises using set relationships and disjointness.
Given Data / Assumptions:
- All Tigers are Jungles (T ⊆ J).
- No Jungle is a Bird (J ∩ B = ∅).
- Some Birds are Rains (∃ B ∩ R).
Concept / Approach:
- If A ⊆ B and B is disjoint from C, then A is disjoint from C.
- “Some” statements do not force anything about the rest of the set outside the specified overlap.
Step-by-Step Solution:
From T ⊆ J and J ∩ B = ∅, it follows immediately that T ∩ B = ∅. So “No bird is a tiger” (III) must be true.Regarding (I) and (II): We only know some Birds are Rains. Those particular Birds are not Jungles, but other parts of Rains might still intersect (or not intersect) Jungles. The premises do not settle whether any Rain is a Jungle.Therefore neither “No rain is a jungle” (I) nor “Some rains are jungles” (II) is forced.
Verification / Alternative check:
Create two models: (a) Rains entirely within Birds; then I holds and II fails. (b) Split Rains into two parts, one overlapping Jungles outside Birds; then II holds and I fails. Since premises allow both models, neither I nor II necessarily follows, but III always does.
Why Other Options Are Wrong:
Options including I or II claim more than warranted. “All follow” is too strong.
Common Pitfalls:
Assuming the “some Birds are Rains” exhaustively describes Rains; it does not.
Final Answer:
Only III follows
Discussion & Comments