GCAT Logical Deduction Problems 5 — Questions and Answers
Question 1: A survey shows: everyone who jogs also stretches. Half of those who stretch also lift weights. Tom jogs. What must be true about Tom?
- Tom lifts weights
- Tom stretches (Correct answer)
- Tom lifts weights and stretches
- Tom does not lift weights
Correct answer: Tom stretches
Jogging guarantees stretching, but whether Tom also lifts weights is not certain from 'half' — only stretching is guaranteed.
Question 2: In a race, P finished before Q. R finished after S. S finished before P. What is the correct finishing order?
- R, S, P, Q
- S, R, P, Q
- S, P, Q, R
- S, P, R, Q (Correct answer)
Correct answer: S, P, R, Q
S before P before Q is fixed; R is after S but the constraints allow R after Q, giving S, P, Q, R or S, P, R, Q — the only fully consistent order with all constraints is S, P, R, Q.
Question 3: No herbivores eat meat. Cows are herbivores. Bessie is a cow. Which conclusion is valid?
- Bessie sometimes eats meat
- Bessie does not eat meat (Correct answer)
- Bessie may eat meat
- Some cows eat meat
Correct answer: Bessie does not eat meat
Bessie is a cow, cows are herbivores, and no herbivores eat meat — so Bessie does not eat meat.
Question 4: Exactly one of these three people is lying: Alex, Blake, Chris. Alex says 'I am telling the truth.' Blake says 'Alex is lying.' Chris says 'Blake is lying.' Who is lying?
- Alex
- Blake (Correct answer)
- Chris
- Cannot be determined
Correct answer: Blake
If Blake is the liar, Alex tells truth (consistent), and Chris tells truth about Blake lying — exactly one liar, so Blake is the liar.
Question 5: A committee selects members under this rule: if X is chosen, Y must also be chosen. Y was not chosen. What can you conclude?
- X was chosen
- X was not chosen (Correct answer)
- X may or may not have been chosen
- Y will be chosen later
Correct answer: X was not chosen
By contrapositive, if Y is not chosen, then X cannot be chosen.
Question 6: All squares are rectangles. Figure Z is not a rectangle. Which conclusion must follow?
- Figure Z is a square
- Figure Z may be a square
- Figure Z is not a square (Correct answer)
- Figure Z is a triangle
Correct answer: Figure Z is not a square
Since every square is a rectangle and Z is not a rectangle, Z cannot be a square.
Question 7: Five items are ranked 1–5 (1 = best). Item M ranks higher than N. Item O ranks lower than P. P ranks higher than M. Which item is ranked 1st?
- M
- N
- O
- P (Correct answer)
Correct answer: P
P ranks higher than M, and M ranks higher than N — P is the highest in its chain, so P is ranked 1st.
GCAT Logical Deduction Problems 5
A survey shows: everyone who jogs also stretches.
Half of those who stretch also lift weights.
Tom jogs.
What must be true about Tom?