GCAT Logical Deduction Problems 2 — Questions and Answers
Question 1: All doctors are scientists. Some scientists are artists. Which conclusion must be true?
- All doctors are artists
- Some doctors are artists
- Some scientists are doctors (Correct answer)
- No doctors are artists
Correct answer: Some scientists are doctors
Since all doctors are scientists, at least some scientists must be doctors.
Question 2: If it is not raining, Maria goes jogging. Maria did not go jogging today. What can you conclude?
- It is raining today (Correct answer)
- Maria is sick
- It might or might not be raining
- Maria went swimming instead
Correct answer: It is raining today
By contrapositive, if Maria did not jog, then it must be raining.
Question 3: Five students — A, B, C, D, E — sit in a row. A is to the left of B. C is to the right of D. B is to the left of D. Who can be in the middle (3rd position)?
- A
- B
- D (Correct answer)
- E
Correct answer: D
The order A-B-D is forced, and C is to D's right, so a valid arrangement is A-B-D-C with E anywhere, placing D third.
Question 4: No reptiles are warm-blooded. All snakes are reptiles. Which statement is definitely true?
- Some snakes are warm-blooded
- All warm-blooded animals are snakes
- No snakes are warm-blooded (Correct answer)
- Some reptiles are snakes
Correct answer: No snakes are warm-blooded
Since snakes are reptiles and no reptiles are warm-blooded, no snakes can be warm-blooded.
Question 5: A store offers a discount only if a customer spends more than $100 OR uses a coupon. Tom received a discount but did not use a coupon. What must be true?
- Tom spent exactly $100
- Tom spent more than $100 (Correct answer)
- Tom used a different coupon
- Tom is a loyalty member
Correct answer: Tom spent more than $100
Since the coupon condition was not met, the other condition (spending over $100) must have been satisfied.
Question 6: All members of Club X play chess. No chess players ride motorcycles. James rides a motorcycle. Which conclusion follows?
- James plays chess
- James is a member of Club X
- James is not a member of Club X (Correct answer)
- James is not a chess player only
Correct answer: James is not a member of Club X
James rides a motorcycle, so he cannot play chess, and therefore cannot be a Club X member.
Question 7: In a logic puzzle: P implies Q. Q implies R. R is false. What can you conclude about P?
- P is true
- P is false (Correct answer)
- P may be true or false
- P implies R directly
Correct answer: P is false
By contrapositive, not-R implies not-Q, and not-Q implies not-P, so P must be false.
GCAT Logical Deduction Problems 2
All doctors are scientists.
Some scientists are artists.
Which conclusion must be true?