Difficulty: Medium
Correct Answer: Only II follows
Explanation:
Introduction / Context:
Here multiple set relations appear together. The safe path is to identify conclusions supported by a single chain using the same existential witness, and to reject conclusions that require intersections not guaranteed by the premises.
Given Data / Assumptions:
Concept / Approach:
From “Some engineers are lawyers” and “All engineers are businessmen,” pick that same engineer as the witness; they are both a businessman and a lawyer. That confirms “Some businessmen are lawyers.” Intersections involving Teachers require existence of Teachers (not stated) and further overlap with Doctors or Businessmen (also not stated).
Step-by-Step Solution:
Verification / Alternative check:
Construct a model with engineers (hence businessmen) who are lawyers, some doctors who are lawyers, and zero teachers. All premises hold and only II is forced.
Why Other Options Are Wrong:
Any option including I, III, or IV assumes extra existence/overlap not ensured by the premises.
Common Pitfalls:
Assuming existence for a class mentioned only in a universal statement (“All teachers are lawyers”) and over-connecting different “some” statements.
Final Answer:
Only II follows.
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