Syllogism – Negative and unrelated premises: Statements: All goats are flowers. No flower is a branch. Some branches are roots. Conclusions: I) Some roots are goats. II) No roots are goat. Choose the option that necessarily follows.

Difficulty: Medium

Correct Answer: Neither Conclusion I nor II follows

Explanation:


Introduction / Context:
We combine one universal positive, one universal negative, and a particular about a fourth set. The risk is over-extending the “no” relation.



Given Data / Assumptions:

  • Goats ⊆ Flowers.
  • Flowers ∩ Branches = ∅.
  • ∃ Branches∩Roots.


Concept / Approach:
The key observation: the only link to Roots is through Branches, and Branches are disjoint from Flowers (hence from Goats). Roots may extend beyond Branches, but nothing connects Roots to Flowers/Goats.



Step-by-Step Solution:
C1: “Some roots are goats.” Not forced. Branches∩Roots elements cannot be Goats (since Branches disjoint Flowers). Roots outside Branches might be Goats, but that is unconstrained; hence not necessary.C2: “No roots are goat.” Also not forced; Roots could include a flower region (and thus goats) outside Branches. No premise forbids that.



Verification / Alternative check:
Construct Model A with Roots overlapping only Branches: then 0 Roots are Goats. Construct Model B with Roots also overlapping Flowers (outside Branches): then some Roots are Goats. Since both models satisfy the premises, neither C1 nor C2 is necessary.



Why Other Options Are Wrong:
Any claim that one conclusion follows is contradicted by a countermodel; “Either” is invalid because both can fail depending on the model.



Common Pitfalls:
Assuming Roots are confined to Branches simply because “some branches are roots.”



Final Answer:
Neither Conclusion I nor II follows.

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