Which argument contains a logical fallacy? Premise: All birds fly. Penguins are birds.

Therefore, some birds do not fly.

Therefore, flying is a bird trait.

Therefore, penguins are animals.

A teacher says: 'If students complete homework, they will pass.' Sam passed. What can be concluded?

Sam didn't need homework to pass.

HEC HAT-General (Religious Studies) analytical reasoning Critical Thinking Set 3

HEC HAT-General (Religious Studies) analytical reasoning Critical Thinking — Set 3

Question 1
Q1. A doctor states: 'If a patient has a fever, they need hydration.' A child has a fever. What must be true?
- A) The child needs hydration.
- B) The child is dehydrated.
- C) Hydration cures fever.
- D) Fever indicates infection.
Answer: The child needs hydration.
Explanation: Direct application of modus ponens (If P→Q, P→Q). Option B adds unproven assumption about dehydration.
Question 2
Q2. Which argument contains a logical fallacy? Premise: All birds fly. Penguins are birds.
- A) Therefore, penguins fly.
- B) Therefore, some birds do not fly.
- C) Therefore, flying is a bird trait.
- D) Therefore, penguins are animals.
Answer: Therefore, penguins fly.
Explanation: Premise is false (penguins don't fly). Therefore, penguins fly is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 3
Q3. Given: No reptiles are mammals. All lizards are reptiles. Which conclusion is valid?
- A) Lizards are not mammals.
- B) Mammals are lizards.
- C) Some lizards are mammals.
- D) Reptiles and mammals overlap.
Answer: Lizards are not mammals.
Explanation: Transitive exclusion applies (Lizards⊂Reptiles⊄Mammals). Lizards are not mammals is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 4
Q4. If all A are B and some B are C, which must be true?
- A) Some A are C.
- B) All C are B.
- C) No A are C.
- D) Some B are A.
Answer: Some B are A.
Explanation: Original premises confirm A⊂B. Is converse of first premise. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 5
Q5. A teacher says: 'If students complete homework, they will pass.' Sam passed. What can be concluded?
- A) Sam completed homework.
- B) Homework guarantees passing.
- C) Sam didn't need homework to pass.
- D) Passing requires homework.
Answer: Passing requires homework.
Explanation: Passing implies homework completion is necessary (converse fallacy in A). USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 6
Q6. All cars require fuel. My vehicle is a car. Which follows logically?
- A) My vehicle requires fuel.
- B) Fuel is only for cars.
- C) My vehicle uses electricity.
- D) Non-car vehicles don't need fuel.
Answer: My vehicle requires fuel.
Explanation: Direct deduction from premises. My vehicle requires fuel is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 7
Q7. Which scenario violates logical consistency? 'If a shape is a square, it is a rectangle.'
- A) A square is a rectangle.
- B) A rectangle is not a square.
- C) Some rectangles are squares.
- D) All squares are rectangles.
Answer: A rectangle is not a square.
Explanation: Statement B contradicts definition of squares as a subset of rectangles. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 8
Q8. Given: All X are Y. Some Y are Z. Which conclusion is invalid?
- A) Some X are Z.
- B) All Z are Y.
- C) Some Y are X.
- D) No X are Z.
Answer: Some X are Z.
Explanation: Overlap between X and Z isn't guaranteed. Option B is converse of premises.
Question 9
Q9. A student claims: 'If a compound is ionic, it conducts electricity. Sodium chloride conducts electricity.' What conclusion follows?
- A) Sodium chloride is ionic.
- B) Ionic compounds are always solid.
- C) Conductivity implies ionic bonding.
- D) Sodium chloride is a metal.
Answer: Sodium chloride is ionic.
Explanation: Modus ponens applies. Sodium chloride is ionic is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 10
Q10. All metals conduct heat. Copper is a metal. Which is logically valid?
- A) Copper conducts heat.
- B) Only copper conducts heat.
- C) Non-metals don't conduct heat.
- D) Heat conduction defines metals.
Answer: Copper conducts heat.
Explanation: Direct deduction from premises. Copper conducts heat is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 11
Q11. If no A are B and some C are A, which must be true?
- A) Some C are not B.
- B) All C are B.
- C) No C are A.
- D) Some B are A.
Answer: Some C are not B.
Explanation: C's overlap with A excludes them from B. Option B contradicts premises.
Question 12
Q12. A biologist states: 'If a cell has a nucleus, it is eukaryotic.' A cell lacks a nucleus. What follows?
- A) It is not eukaryotic.
- B) It is prokaryotic.
- C) It has no organelles.
- D) Nucleus is unnecessary for life.
Answer: It is not eukaryotic.
Explanation: Modus tollens applies (¬Q→¬P). It is not eukaryotic is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 13
Q13. Given: All P are Q. No Q are R. Which conclusion is valid?
- A) No P are R.
- B) Some P are R.
- C) All R are P.
- D) Q and R overlap.
Answer: No P are R.
Explanation: Transitive exclusivity applies (P⊂Q⊄R). No P are R is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 14
Q14. If all vertebrates have a backbone and all mammals are vertebrates, which is valid?
- A) All mammals have backbones.
- B) Some mammals lack backbones.
- C) Backbones define vertebrates.
- D) Mammals are not vertebrates.
Answer: All mammals have backbones.
Explanation: Transitive inclusion applies. All mammals have backbones is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 15
Q15. A student claims: 'If a solution is acidic, it turns litmus red. Litmus turned red.' What follows?
- A) The solution is acidic.
- B) Acids always turn litmus red.
- C) The solution is not basic.
- D) Red litmus indicates acidity.
Answer: The solution is acidic.
Explanation: Affirming the consequent (invalid). The solution is acidic is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 16
Q16. Given: Some A are B. All B are C. Which conclusion is invalid?
- A) Some A are C.
- B) All C are B.
- C) Some C are A.
- D) No A are C.
Answer: All C are B.
Explanation: B⊂C but C⊄B. Is converse of premise. All C are B is correct because it matches what the question requires. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 17
Q17. If a triangle has equal angles, it is equilateral. A triangle is not equilateral. What follows?
- A) Its angles are unequal.
- B) It has one right angle.
- C) All angles are 60°.
- D) It has two equal sides.
Answer: Its angles are unequal.
Explanation: Modus tollens applies. Option D describes an isosceles triangle, not excluded by premises.
Question 18
Q18. If all reptiles lay eggs and snakes are reptiles, which conclusion is valid?
- A) Snakes lay eggs
- B) Some reptiles do not lay eggs
- C) All egg-laying animals are reptiles
- D) Birds are reptiles
Answer: Snakes lay eggs
Explanation: Syllogism applies. B contradicts premise. C is converse fallacy. D is unrelated category
Question 19
Q19. Given: If it rains, the ground is wet. The ground is dry. What logically follows?
- A) It did not rain
- B) It rained but evaporated
- C) The ground is made of concrete
- D) Rainwater was absorbed
Answer: It did not rain
Explanation: Modus tollens applies. B introduces unsupported facts. C/D are irrelevant material. USAT, HAT and MDCAT analytical sections repeat this pattern.
Question 20
Q20. Premise 1: All mammals have hair. Premise 2: Bats have hair. What is the logical structure used to conclude bats are mammals?
- A) Affirming the consequent
- B) Denying the antecedent
- C) Hypothetical syllogism
- D) Disjunctive syllogism
Answer: Affirming the consequent
Explanation: Valid in formal logic but not reliable. B is irrelevant. C/D require conditional chains