Watson-Glaser Critical Thinking Appraisal Drawing Deductive Conclusions Questions and Answers 4 — Questions and Answers
Question 1: Premises: All physicians are college graduates. Some college graduates are wealthy. Conclusion: Some physicians are wealthy.
- The conclusion follows
- The conclusion does not follow (Correct answer)
- The conclusion is probably true
- The conclusion requires more premises
Correct answer: The conclusion does not follow
The 'some wealthy college graduates' may not overlap with physicians at all, so wealth among physicians cannot be deduced.
Question 2: Premises: Either the project is on schedule or it is over budget. The project is not over budget. Conclusion: The project is on schedule.
- The conclusion follows (Correct answer)
- The conclusion does not follow
- The conclusion is only probably true
- The conclusion contradicts the premises
Correct answer: The conclusion follows
This is a valid disjunctive syllogism: given A or B, and not B, A must be true.
Question 3: Premises: All animals that are mammals breathe air. Whales breathe air. Conclusion: Whales are mammals.
- The conclusion follows
- The conclusion does not follow (Correct answer)
- The conclusion is logically necessary
- The premises entail the conclusion
Correct answer: The conclusion does not follow
Breathing air is a property of all mammals but may also apply to non-mammals, so the conclusion commits the fallacy of affirming the consequent.
Question 4: Premises: No fast-food restaurant in the city serves lobster. The Harbor Grill is in the city and serves lobster. Conclusion: The Harbor Grill is not a fast-food restaurant.
- The conclusion follows (Correct answer)
- The conclusion does not follow
- The conclusion is only probably true
- The premises are contradictory
Correct answer: The conclusion follows
By contraposition: if it served lobster and no fast-food restaurant in the city does, then it cannot be a fast-food restaurant.
Question 5: Premises: All red cards in the deck are hearts or diamonds. This card is a spade. Conclusion: This card is not red.
- The conclusion follows (Correct answer)
- The conclusion does not follow
- More information is required
- The conclusion is possibly false
Correct answer: The conclusion follows
Since all red cards are hearts or diamonds, a spade cannot be red — the conclusion follows validly by modus tollens.
Question 6: Premises: Most successful startups receive venture capital funding. TechLaunch is a successful startup. Conclusion: TechLaunch received venture capital funding.
- The conclusion follows
- The conclusion does not follow (Correct answer)
- The conclusion is certainly true
- The conclusion is certainly false
Correct answer: The conclusion does not follow
'Most' means more than half but not all, so individual cases cannot be deduced with certainty even when the general trend is strong.
Question 7: Premises: If a number is divisible by 4, it is divisible by 2. The number 18 is divisible by 2. Conclusion: 18 is divisible by 4.
- The conclusion follows
- The conclusion does not follow (Correct answer)
- The conclusion is necessarily true
- The premises support the conclusion
Correct answer: The conclusion does not follow
The conditional only goes one direction; divisibility by 2 does not imply divisibility by 4, making this the fallacy of affirming the consequent.
Watson-Glaser Critical Thinking Appraisal Drawing Deductive Conclusions Questions and Answers 4
Premises: All physicians are college graduates.
Some college graduates are wealthy.
Conclusion: Some physicians are wealthy.