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Complementary statements about wealth and poverty: From 'No gentleman is poor' and 'All gentlemen are rich', decide whether the conclusions (I) 'No poor man is rich' and (II) 'No rich man is poor' necessarily follow.

Difficulty: Medium

Correct Answer: Neither I nor II follows

Explanation:

Given data

  • Premise 1: Gentleman ∩ Poor = ∅.
  • Premise 2: Gentleman ⊆ Rich.
  • Conclusions: (I) No Poor is Rich. (II) No Rich is Poor.

Concept/Approach

The premises restrict relations involving the subset 'Gentleman', not the entire sets 'Rich' or 'Poor'. Without information about non-gentlemen, we cannot generalize to all rich or all poor.

Step-by-step evaluation

1) From Premise 1 & 2: Gentlemen are rich and not poor.2) But there may exist rich non-gentlemen who could or could not be poor (no info given).3) Hence both universal claims (I) and (II) are not derivable.

Verification/Alternative

Countermodel: Let Gentlemen = {g1}, Rich = {g1, r2}, Poor = {r2}. Premises hold (g1 rich, not poor), yet (I) is false (r2 is both rich and poor in a definitional sense) and (II) is false. Therefore no conclusion is necessary.

Common pitfalls

  • Overextending results from a subset (Gentleman) to the whole set (Rich/Poor).

Final Answer
Neither I nor II follows.

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