Difficulty: Easy
Correct Answer: Both I and II follow.
Explanation:
Introduction / Context:
Universal inclusion plus universal exclusion often yields two clear consequences: a complement statement and a propagated exclusion along the subset chain.
Given Data / Assumptions:
Concept / Approach:
If every man is employed, then no man is unemployed (I). And since no employee is a professional, no man (being an employee) can be a professional (II).
Step-by-Step:
1) From Man ⊆ Employed, conclude Man ∩ Unemployed = ∅ → I.2) From Man ⊆ Employed and Employed ∩ Professional = ∅, infer Man ∩ Professional = ∅ → II.
Common Pitfalls:
Forgetting that exclusions applying to a superset automatically apply to all its subsets.
Final Answer:
Both I and II follow.
Discussion & Comments