GCAT Syllogistic Reasoning 4 — Questions and Answers
Question 1: All fast runners are fit. Tom is not fit. What follows about Tom?
- Tom is a fast runner.
- Tom is not a fast runner. (Correct answer)
- Tom might be a fast runner.
- Tom is sometimes a fast runner.
Correct answer: Tom is not a fast runner.
By contrapositive, if someone is not fit then they are not a fast runner.
Question 2: Some roses are red. All red flowers are beautiful. Which must be true?
- All roses are beautiful.
- Some roses are beautiful. (Correct answer)
- No roses are beautiful.
- All beautiful things are roses.
Correct answer: Some roses are beautiful.
The red roses must be beautiful, making at least some roses beautiful.
Question 3: All A are B. Some B are C. No C are D. Which is a valid conclusion about A and D?
- All A are D.
- Some A are D.
- No conclusion about A and D. (Correct answer)
- No A are D.
Correct answer: No conclusion about A and D.
Since 'some B are C' is particular, we cannot determine whether any A fall in that subset, making a conclusion about A and D impossible.
Question 4: No lazy person succeeds. All successors are respected. Which is valid?
- All lazy people are respected.
- No lazy person is respected.
- Some lazy people are respected.
- No conclusion about lazy and respected. (Correct answer)
Correct answer: No conclusion about lazy and respected.
The premises don't connect lazy people to the respected group — lazy people are outside the successor set, but we don't know if the respected group extends beyond successors.
Question 5: All judges are lawyers. All lawyers passed the bar. Sandra passed the bar. What follows?
- Sandra is a judge.
- Sandra is a lawyer.
- Sandra might be a judge. (Correct answer)
- Sandra is definitely not a judge.
Correct answer: Sandra might be a judge.
Passing the bar is necessary but not sufficient to be a lawyer or judge, so Sandra might or might not be a judge.
Question 6: Some engineers are creative. Some creative people are musicians. Which is valid?
- Some engineers are musicians.
- All engineers are musicians.
- No conclusion about engineers and musicians. (Correct answer)
- All musicians are engineers.
Correct answer: No conclusion about engineers and musicians.
Two particular premises sharing a middle term yield no valid conclusion.
Question 7: All planets orbit a star. Earth orbits the Sun. The Sun is a star. Which conclusion is supported?
- Earth is a planet.
- Earth might be a planet. (Correct answer)
- Earth is the only planet.
- The Sun is a planet.
Correct answer: Earth might be a planet.
Earth meets the stated condition for being a planet, but the syllogism only confirms the condition is met, not the classification itself with certainty.
GCAT Syllogistic Reasoning 4
All fast runners are fit.
Tom is not fit.
What follows about Tom?