(50 MCQs with Solutions)
Section A – Nature of Reasoning & Arguments (Q 1–10)
Q1. Which of the following is not a part of an argument?
A) Premise B) Assumption C) Conclusion D) Question
Answer: D
Solution: An argument contains premises and conclusion; a question is not an assertion, hence not part of argument structure.
Q2. Which of the following words generally introduces a conclusion?
A) Since B) Because C) Therefore D) Given that
Answer: C
Solution: “Therefore,” “Thus,” and “Hence” signal conclusions.
Q3. Statement: All cats are animals.
The subject term is ____ and predicate term is ____.
A) Cats – Animals B) Animals – Cats C) All – Cats D) None
Answer: A
Q4. “No politician is honest” is which type of categorical proposition?
A) A B) E C) I D) O
Answer: B
Solution: Universal negative (E-type).
Q5. A valid deductive argument:
A) May have false premises but true conclusion.
B) Cannot have true premises and false conclusion.
C) May have true premises and false conclusion.
D) Must be factually true.
Answer: B
Solution: Validity = if premises are true, conclusion must be true.
Q6. “All poets are sensitive. Some sensitive people are foolish.”
→ Conclusion: Some poets are foolish.
Valid or Invalid?
Answer: Invalid.
Solution: No direct overlap shown between poets and foolish; fallacy of undistributed middle.
Q7. The reasoning “All metals expand on heating; iron is a metal; therefore iron expands” is:
A) Deductive B) Inductive C) Abductive D) Analogy
Answer: A
Q8. In logic, truth refers to:
A) Personal belief B) Empirical proof C) Agreement of statement with fact D) Social approval
Answer: C
Q9. “The road is wet, therefore it must have rained.” This is an example of:
A) Deductive B) Inductive C) Abductive D) Fallacy
Answer: C
Solution: Inference to the best explanation (abduction).
Q10. Inductive reasoning provides conclusions that are:
A) Certain B) Probable C) Always false D) Deductive
Answer: B
Section B – Propositions & Square of Opposition (Q 11–20)
Q11. “Some students are hardworking.” → Which proposition?
A) A B) E C) I D) O
Answer: C (Particular affirmative)
Q12. Contradictory of “All S are P” is ____.
A) Some S are P B) No S are P C) Some S are not P D) Some S are not non-P
Answer: C
Q13. From “No dogs are cats,” we may infer:
A) All dogs are not cats B) Some dogs are cats C) Some dogs are not cats D) All cats are dogs
Answer: C
Solution: Universal negative (E) implies particular negative (O) under sub-alternation.
Q14. “All A are B.” Which inference is valid?
A) Some A are B B) Some B are A C) Some A are not B D) No B are A
Answer: A
Q15. Which pairs are contradictory?
A) A & E B) A & O C) E & I D) B & O
Answer: B
Q16. Two propositions that cannot both be true but may both be false are:
A) Contrary B) Contradictory C) Sub-contrary D) Equivalent
Answer: A
Q17. In the square of opposition, truth flows downward in:
A) Contrary B) Sub-alternation C) Contradiction D) Sub-contrary
Answer: B
Q18. “Some trees are not green” → Type?
A) O-proposition B) A C) I D) E
Answer: A
Q19. “All flowers are plants” and “No flowers are plants” are ____.
A) Contrary B) Contradictory C) Sub-contrary D) Equivalent
Answer: A
Q20. “Some birds are not sparrows” contradicts ____.
A) All birds are sparrows B) No birds are sparrows C) Some birds are sparrows D) All sparrows are birds
Answer: A
Section C – Syllogism & Venn Reasoning (Q 21–30)
Q21. All mangoes are fruits. All fruits are edible. ∴ All mangoes are edible.
Answer: Valid (syllogism, AAA figure 1 – Barbara)
Q22. Some flowers are red. All red things are beautiful. ∴ Some flowers are beautiful.
Answer: Valid (IAI – Darii)
Q23. All students are learners. Some learners are teachers. ∴ Some students are teachers.
Answer: Invalid (fallacy of undistributed middle)
Q24. All A are B; No B are C ⇒ No A are C.
Answer: Valid (EAE – Celarent)
Q25. In a Venn diagram, if circles A and B overlap partly, it represents:
A) All A are B B) Some A are B C) No A are B D) All B are A
Answer: B
Q26. “Some A are B and some B are C → Some A are C.”
Answer: Invalid (‘Some–Some’ cannot yield a definite conclusion).
Q27. For a valid syllogism, the middle term must be
A) Distributed once at least B) Never distributed C) Always distributed twice D) None
Answer: A
Q28. The syllogism “No cats are dogs; All dogs are animals ⇒ No cats are animals” is
A) Valid B) Invalid C) Partially true D) Inductive
Answer: B
Q29. All philosophers are thinkers; Some thinkers are teachers ⇒ ?
Answer: Cannot be concluded (undistributed middle).
Q30. In Venn analysis, “No A are B” → the circles are ____.
A) One inside other B) Separate C) Overlapping D) Equal
Answer: B
Section D – Fallacies & Types of Reasoning (Q 31–38)
Q31. “All doctors are educated; Mr. X is educated; ∴ Mr. X is doctor.” → Fallacy of ____.
Answer: Undistributed middle.
Q32. “He is wrong because he is young.”
Answer: Ad Hominem fallacy (attacking person not argument).
Q33. “Post hoc ergo propter hoc” means ____.
Answer: False cause – assuming that after ⇒ therefore because of.
Q34. “If the new phone is expensive, it must be good.” → Fallacy of ____.
Answer: False cause / Hasty generalization.
Q35. “Either you are with us or against us.” → Fallacy of ____.
Answer: False dilemma.
Q36. “He is a scientist, so whatever he says is true.” → Fallacy of ____.
Answer: Appeal to authority.
Q37. “Circular reasoning” occurs when ____.
Answer: The conclusion repeats the premise in different words.
Q38. Deductive reasoning ensures ____.
Answer: Necessity of conclusion if premises are true.
Section E – Indian Logic (Q 39–50)
Q39. “Means of valid knowledge” in Indian logic is called ____.
A) Hetu B) Pramāṇa C) Vyāpti D) Prameya
Answer: B
Q40. How many Pramāṇas are accepted in Nyāya school?
A) 2 B) 3 C) 4 D) 5
Answer: C (Pratyakṣa, Anumāna, Śabda, Upamāna)
Q41. Match the following:
-
Pratyakṣa → (a) Perception
-
Anumāna → (b) Inference
-
Upamāna → (c) Comparison
Answer: 1-a, 2-b, 3-c
Q42. The universal concomitance between reason and probandum is called ____.
Answer: Vyāpti.
Q43. In five-member syllogism, the first statement is called ____.
Answer: Pratijñā (proposition).
Q44. Correct sequence of Indian inference (Anumāna):
1 Pratijñā, 2 Hetu, 3 Udāharaṇa, 4 Upanaya, 5 Nigamana.
Answer: As listed.
Q45. “Hill has fire because it has smoke.” → ‘Smoke’ is ____.
Answer: Hetu (reason).
Q46. Fallacy where reason is unproved (asiddha) means ____.
Answer: Unestablished middle term – Hetu does not exist.
Q47. “Fire is cold because it is a substance.” → Fallacy type ____.
Answer: Viruddha (contradictory reason).
Q48. “There is fire on hill because there is smoke and smoke is always with fire.” → Here ‘Smoke is always with fire’ shows ____.
Answer: Vyāpti (universal relation).
Q49. “Absence of sound means no vibration.” Knowledge by absence is called ____.
Answer: Anupalabdhi.
Q50. The fallacy where hetu is inconclusive (non-exclusive) is ____.
Answer: Anaikāntika.