Propositional Logic: Logical Arguments and Soundness
This quiz evaluates your understanding of propositional logic, logical arguments, and the concept of soundness.
Questions
Which of the following is a propositional variable?
- A
- B
- C
- D
What is the truth value of the proposition "2 + 2 = 5"?
- True
- False
Which of the following is a logical connective?
- And
- Or
- Not
- If-then
What is the truth value of the compound proposition "(P ∧ Q) ∨ ¬R" if P is true, Q is false, and R is true?
- True
- False
Which of the following is a valid logical argument?
- If it is raining, then the ground is wet.
- The ground is wet, therefore it is raining.
- If it is raining, then the sky is blue.
- The sky is blue, therefore it is raining.
What is the difference between a sound and an unsound logical argument?
- A sound argument has true premises and a true conclusion.
- An unsound argument has false premises and a false conclusion.
- A sound argument has true premises and a false conclusion.
- An unsound argument has false premises and a true conclusion.
Which of the following is an example of a sound logical argument?
- All men are mortal.
- Socrates is a man.
- Therefore, Socrates is mortal.
- All dogs are mammals.
- Cats are not dogs.
- Therefore, cats are not mammals.
Which of the following is an example of an unsound logical argument?
- All birds can fly.
- Penguins are birds.
- Therefore, penguins can fly.
- All fruits contain seeds.
- Tomatoes are fruits.
- Therefore, tomatoes contain seeds.
What is the converse of the proposition "If it is raining, then the ground is wet"?
- If the ground is wet, then it is raining.
- If it is not raining, then the ground is not wet.
- If the ground is not wet, then it is not raining.
- If it is raining, then the ground is not wet.
What is the inverse of the proposition "If it is raining, then the ground is wet"?
- If it is not raining, then the ground is not wet.
- If the ground is wet, then it is raining.
- If the ground is not wet, then it is not raining.
- If it is raining, then the ground is not wet.
What is the contrapositive of the proposition "If it is raining, then the ground is wet"?
- If the ground is wet, then it is raining.
- If it is not raining, then the ground is not wet.
- If the ground is not wet, then it is not raining.
- If it is raining, then the ground is not wet.
Which of the following is a tautology?
- (P ∨ ¬P)
- (P ∧ ¬P)
- (P → Q) ∨ (¬P → Q)
- (P → Q) ∧ (¬P → ¬Q)
Which of the following is a contradiction?
- (P ∨ ¬P)
- (P ∧ ¬P)
- (P → Q) ∨ (¬P → Q)
- (P → Q) ∧ (¬P → ¬Q)
What is the law of detachment?
- If P → Q and P, then Q.
- If P → Q and ¬Q, then ¬P.
- If P ∨ Q and P, then Q.
- If P ∨ Q and ¬P, then Q.
What is the law of syllogism?
- If P → Q and Q → R, then P → R.
- If P → Q and ¬Q, then ¬P.
- If P ∨ Q and P, then Q.
- If P ∨ Q and ¬P, then Q.