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

Which of the following is an example of an inductive argument?

  1. All men are mortal. Socrates is a man. Therefore, Socrates is mortal.

  2. The sun has risen every day for the past 10,000 years. Therefore, the sun will rise tomorrow.

  3. I have seen a black swan. Therefore, all swans are black.

  4. The grass is green. The sky is blue. Therefore, the world is a beautiful place.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is an example of an inductive argument because it uses evidence from the past to make a generalization about the future. The sun has risen every day for the past 10,000 years. Therefore, the sun will rise tomorrow.

Multiple choice

Which of the following is a fallacy?

  1. Affirming the consequent

  2. Denying the antecedent

  3. Modus ponens

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

Affirming the consequent is a fallacy because it does not guarantee that the conclusion is true. For example, if we have the premise "If it is raining, then the ground is wet" and the consequent "The ground is wet", we cannot conclude that it is raining.

Multiple choice

In Nyaya philosophy, what is the term for the logical fallacy of denying the antecedent?

  1. Vyapti

  2. Hetvabhasa

  3. Anumana

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

Hetvabhasa, in Nyaya, refers to a logical fallacy in which the antecedent of a conditional statement is denied, leading to an erroneous conclusion.

Multiple choice

Which of the following is a valid argument form?

  1. If P, then Q.

  2. P, therefore Q.

  3. If P, then Q.

  4. Q, therefore P.
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

A valid argument form is one in which the conclusion follows logically from the premises. In this case, if P is true, then Q must also be true. Therefore, the argument form is valid.

Multiple choice

Which of the following is a fallacy?

  1. Affirming the consequent

  2. Denying the antecedent

  3. Modus ponens

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

Affirming the consequent is a fallacy in which the conclusion is drawn that P must be true because Q is true. However, this is not necessarily the case. For example, if we know that "If it is raining, then the ground is wet", we cannot conclude that "The ground is wet, therefore it is raining."

Multiple choice

What is the conclusion of the following syllogism?

  1. If P, then Q.

  2. P, therefore Q.

  3. If P, then Q.

  4. Q, therefore P.
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

A syllogism is a logical argument that consists of two premises and a conclusion. In this case, the premises are "If P, then Q" and "P". The conclusion is therefore "Q".

Multiple choice

Which of the following is an example of a conditional syllogism?

  1. If it is raining, then the ground is wet.

  2. The ground is wet, therefore it is raining.

  3. If it is raining, then the ground is wet.

  4. It is raining, therefore the ground is wet.
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

A conditional syllogism is a syllogism in which the major premise is a conditional statement. In this case, the major premise is "If it is raining, then the ground is wet."

Multiple choice

Which of the following is an example of a disjunctive syllogism?

  1. Either it is raining or the sun is shining.

  2. It is raining, therefore the sun is not shining.

  3. Either it is raining or the sun is shining.

  4. The sun is shining, therefore it is not raining.
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

A disjunctive syllogism is a syllogism in which the major premise is a disjunctive statement. In this case, the major premise is "Either it is raining or the sun is shining."

Multiple choice

Which of the following is an example of a hypothetical syllogism?

  1. If it is raining, then the ground is wet.

  2. The ground is wet, therefore it is raining.

  3. If it is raining, then the ground is wet.

  4. It is raining, therefore the ground is wet.
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

A hypothetical syllogism is a syllogism in which the major premise is a hypothetical statement. In this case, the major premise is "If it is raining, then the ground is wet."

Multiple choice

Which of the following is an example of a categorical syllogism?

  1. All men are mortal.

  2. Socrates is a man.

  3. Therefore, Socrates is mortal.

  4. All men are mortal.

  5. Socrates is a man.
Reveal answer Fill a bubble to check yourself
A,D Correct answer
Explanation

A categorical syllogism is a syllogism in which the premises and conclusion are all categorical statements. In this case, the premises are "All men are mortal" and "Socrates is a man". The conclusion is "Therefore, Socrates is mortal."

Multiple choice

Which of the following is an example of a deductive argument?

  1. If it is raining, then the ground is wet.

  2. The ground is wet, therefore it is raining.

  3. If it is raining, then the ground is wet.

  4. It is raining, therefore the ground is wet.
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

A deductive argument is an argument in which the conclusion follows logically from the premises. In this case, if it is raining, then the ground must also be wet. Therefore, the argument is deductive.

Multiple choice

Which of the following is an example of an inductive argument?

  1. All swans are white.

  2. I have seen many white swans.

  3. Therefore, all swans are white.

  4. All swans are white.

  5. I have seen many white swans.
Reveal answer Fill a bubble to check yourself
B,E Correct answer
Explanation

An inductive argument is an argument in which the conclusion is supported by evidence, but does not necessarily follow logically from the premises. In this case, the evidence is that the speaker has seen many white swans. However, this does not necessarily mean that all swans are white.

Multiple choice

Which of the following is an example of a sound argument?

  1. If it is raining, then the ground is wet.

  2. The ground is wet, therefore it is raining.

  3. If it is raining, then the ground is wet.

  4. It is raining, therefore the ground is wet.
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

A sound argument is an argument that is both valid and has true premises. In this case, the argument is valid because the conclusion follows logically from the premises. The premises are also true, because it is a fact that if it is raining, then the ground will be wet. Therefore, the argument is sound.

Multiple choice

Which of the following is an example of an unsound argument?

  1. All men are mortal.

  2. Socrates is a man.

  3. Therefore, Socrates is mortal.

  4. All men are mortal.

  5. Socrates is a man.
Reveal answer Fill a bubble to check yourself
A,D Correct answer
Explanation

An unsound argument is an argument that is either invalid or has false premises. In this case, the argument is invalid because the conclusion does not follow logically from the premises. The premises are also false, because it is not true that all men are mortal. Therefore, the argument is unsound.

Multiple choice

Which of the following is an example of a formal fallacy?

  1. Affirming the consequent

  2. Denying the antecedent

  3. Modus ponens

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

A formal fallacy is a fallacy that is based on the structure of the argument, rather than the content of the premises. Affirming the consequent is a formal fallacy in which the conclusion is drawn that P must be true because Q is true. However, this is not necessarily the case. For example, if we know that "If it is raining, then the ground is wet", we cannot conclude that "The ground is wet, therefore it is raining."