GCAT Logical Deduction Problems 4 — Questions and Answers
Question 1: Six people — F, G, H, I, J, K — are seated in two rows of three facing each other. F faces G. H is to the right of F. I is to the left of G. Who sits opposite H?
- G
- I (Correct answer)
- J
- K
Correct answer: I
F faces G; H is to F's right in one row; I is to G's left in the opposite row, placing I directly opposite H.
Question 2: No cold-blooded animals are mammals. Dolphins are mammals. Which conclusion is logically valid?
- Dolphins are cold-blooded
- Dolphins may be cold-blooded
- Dolphins are not cold-blooded (Correct answer)
- Some mammals are cold-blooded
Correct answer: Dolphins are not cold-blooded
Since dolphins are mammals and no mammals are cold-blooded, dolphins cannot be cold-blooded.
Question 3: Whenever there is fog, flights are delayed. Flights are delayed today. What can you conclude?
- There is definitely fog today
- There is definitely no fog today
- There may or may not be fog today (Correct answer)
- All delays are caused by fog
Correct answer: There may or may not be fog today
Fog causes delays, but delays can have other causes, so fog is not guaranteed from delays alone.
Question 4: All fast runners are good athletes. Mark is not a good athlete. What must be true about Mark?
- Mark is a fast runner
- Mark is not a fast runner (Correct answer)
- Mark may be a fast runner
- Mark is a slow athlete
Correct answer: Mark is not a fast runner
By contrapositive, if Mark is not a good athlete, he cannot be a fast runner.
Question 5: Three friends each prefer a different color: red, blue, or green. Anna does not like red. Ben does not like blue. If Carlos likes green, what does Anna like?
- Red
- Blue (Correct answer)
- Green
- Cannot be determined
Correct answer: Blue
Carlos takes green, leaving red and blue; Anna cannot have red, so Anna must like blue.
Question 6: Statement: 'All honest people keep their promises.' Sandra kept her promise. What can be concluded?
- Sandra is honest
- Sandra may or may not be honest (Correct answer)
- Sandra is not honest
- Sandra always keeps promises
Correct answer: Sandra may or may not be honest
Keeping a promise is a result of being honest, but others who are not honest could also keep promises.
Question 7: If A then B. If B then C. If C then D. A is true. Which set of conclusions must all be true?
- B only
- B and C only
- B, C, and D (Correct answer)
- A, B, C, and D
Correct answer: B, C, and D
Starting from A, each conditional fires in sequence: A→B→C→D, so B, C, and D are all true.
GCAT Logical Deduction Problems 4
Six people — F, G, H, I, J, K — are seated in two rows of three facing each other.
F faces G.
H is to the right of F.
I is to the left of G.
Who sits opposite H?