Watson-Glaser Critical Thinking Appraisal Drawing Deductive Conclusions Questions and Answers 3 ā Questions and Answers
Question 1: Premises: All managers attend the weekly briefing. Sandra is a manager. Conclusion: Sandra attends the weekly briefing.
- The conclusion follows (Correct answer)
- The conclusion does not follow
- The conclusion is probably true but not certain
- More information is needed
Correct answer: The conclusion follows
Since all managers attend and Sandra is a manager, the conclusion follows necessarily by universal instantiation.
Question 2: Premises: No reptiles are warm-blooded. All snakes are reptiles. Conclusion: Some snakes are warm-blooded.
- The conclusion follows
- The conclusion does not follow (Correct answer)
- The conclusion is possibly true
- The premises are contradictory
Correct answer: The conclusion does not follow
If no reptiles are warm-blooded and all snakes are reptiles, then no snakes can be warm-blooded ā so the conclusion contradicts the premises.
Question 3: Premises: If it rains, the game is cancelled. The game was not cancelled. Conclusion: It did not rain.
- The conclusion does not follow
- The conclusion follows (Correct answer)
- The conclusion is probably true
- The conclusion is irrelevant to the premises
Correct answer: The conclusion follows
This is the valid logical form modus tollens: if PāQ and Ā¬Q, then Ā¬P; therefore the conclusion follows.
Question 4: Premises: Some students passed the exam. All students who passed received a certificate. Conclusion: All students received a certificate.
- The conclusion follows
- The conclusion does not follow (Correct answer)
- The conclusion probably follows
- The premises are insufficient
Correct answer: The conclusion does not follow
The premises only guarantee that the students who passed received certificates, not all students, so the conclusion is too strong.
Question 5: Premises: Every employee who works overtime earns a bonus. James earned a bonus. Conclusion: James worked overtime.
- The conclusion follows
- The conclusion does not follow (Correct answer)
- The conclusion is certain given the premises
- The conclusion is a contradiction
Correct answer: The conclusion does not follow
Earning a bonus may have other causes; the premises do not state that overtime is the only way to earn a bonus, so affirming the consequent is a fallacy.
Question 6: Premises: All fruits contain seeds. Bananas are fruits. Conclusion: Bananas contain seeds.
- The conclusion follows (Correct answer)
- The conclusion does not follow
- The conclusion requires additional premises
- The premises are false so no conclusion follows
Correct answer: The conclusion follows
The syllogism is valid: all fruits contain seeds, bananas are fruits, therefore bananas contain seeds ā the conclusion follows from the premises as stated.
Question 7: Premises: No members of the committee voted for the proposal. Helen is not a member of the committee. Conclusion: Helen voted for the proposal.
- The conclusion follows
- The conclusion does not follow (Correct answer)
- The conclusion probably follows
- The conclusion is necessarily false
Correct answer: The conclusion does not follow
The premises only restrict committee members' votes; they say nothing about how non-members voted, so no conclusion about Helen's vote follows.
Watson-Glaser Critical Thinking Appraisal Drawing Deductive Conclusions Questions and Answers 3
Premises: All managers attend the weekly briefing.
Sandra is a manager.
Conclusion: Sandra attends the weekly briefing.