Reasoning

Logic and Fallacies

1,716 Questions

Understand the fundamentals of propositional logic, logical inference rules, and paradoxes. This set includes identifying logical fallacies, including those found in classical Nyaya logic. Strong grasp of these concepts is crucial for scoring well in the reasoning sections of competitive tests.

Propositional logic modelsLogical inference rulesTypes of logical fallaciesParadoxes and contingent truthsNyaya logic concepts

Logic and Fallacies Questions

Multiple choice

What is the name of the epistemic logic axiom that states that knowledge implies truth?

  1. K->B

  2. B->K

  3. T->K

  4. J->K
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The epistemic logic axiom that states that knowledge implies truth is T->K. It expresses the idea that if a proposition is true, then any agent who knows it must also believe it.

Multiple choice

What is the name of the epistemic logic axiom that states that justification implies knowledge?

  1. K->B

  2. B->K

  3. T->K

  4. J->K
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The epistemic logic axiom that states that justification implies knowledge is J->K. It expresses the idea that if an agent is justified in believing a proposition, then they must also know it.

Multiple choice

What is the name of the epistemic logic rule of inference that allows us to infer knowledge of a conjunction from knowledge of its conjuncts?

  1. Conjunction Rule

  2. Disjunction Rule

  3. Modus Ponens

  4. Modus Tollens
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The epistemic logic rule of inference that allows us to infer knowledge of a conjunction from knowledge of its conjuncts is called the Conjunction Rule. It is expressed as follows: If Kφ and Kψ, then K(φ∧ψ).

Multiple choice

What is the name of the epistemic logic rule of inference that allows us to infer knowledge of a disjunction from knowledge of one of its disjuncts?

  1. Conjunction Rule

  2. Disjunction Rule

  3. Modus Ponens

  4. Modus Tollens
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The epistemic logic rule of inference that allows us to infer knowledge of a disjunction from knowledge of one of its disjuncts is called the Disjunction Rule. It is expressed as follows: If Kφ or Kψ, then K(φ∨ψ).

Multiple choice

Which of the following is an example of an epistemic closure principle?

  1. If you know that A, then you know that A or B.

  2. If you know that A, then you know that not A.

  3. If you know that A, then you know that A implies B.

  4. If you know that A, then you know that B implies A.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An epistemic closure principle is a principle that states that if you know a proposition, then you also know all of its logical consequences. The principle 'If you know that A, then you know that A implies B' is an example of an epistemic closure principle.

Multiple choice

Which of the following is an example of a violation of epistemic closure?

  1. You know that all bachelors are unmarried, but you do not know that all unmarried men are bachelors.

  2. You know that all dogs are mammals, but you do not know that all mammals are dogs.

  3. You know that all cats are animals, but you do not know that all animals are cats.

  4. You know that all humans are mortal, but you do not know that all mortals are humans.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A violation of epistemic closure occurs when you know a proposition but do not know one of its logical consequences. The example 'You know that all bachelors are unmarried, but you do not know that all unmarried men are bachelors' is an example of a violation of epistemic closure.