LNAT Argument Evaluation 2 — Questions and Answers
Question 1: A politician argues: 'Crime rates fell after we increased police funding, so the funding caused the drop.' Which flaw best describes this reasoning?
- Circular reasoning
- Post hoc ergo propter hoc (Correct answer)
- Ad hominem
- False dilemma
Correct answer: Post hoc ergo propter hoc
Assuming causation from mere temporal sequence is the post hoc fallacy.
Question 2: Which of the following, if true, most strengthens the argument that banning fast food advertising reduces childhood obesity?
- Fast food tastes good to most children
- Countries with advertising bans show lower childhood obesity rates than comparable countries without bans (Correct answer)
- Obesity has many causes beyond diet
- Children often watch television for several hours daily
Correct answer: Countries with advertising bans show lower childhood obesity rates than comparable countries without bans
Comparative evidence from countries with and without the ban directly supports the causal claim.
Question 3: An argument concludes that all swans are white because every swan ever observed has been white. This is an example of:
- Deductive validity
- Hasty generalization
- Inductive reasoning with a known counterexample risk (Correct answer)
- Straw man
Correct answer: Inductive reasoning with a known counterexample risk
The argument is inductive and could be falsified by a single counterexample, as indeed occurred when black swans were discovered.
Question 4: Which statement best describes the difference between a valid argument and a sound argument?
- A sound argument has true premises; a valid argument need not (Correct answer)
- A valid argument has true premises; a sound argument need not
- Both terms mean the conclusion must be true
- Validity applies only to inductive arguments
Correct answer: A sound argument has true premises; a valid argument need not
Validity means the conclusion follows from the premises; soundness additionally requires the premises to be true.
Question 5: A commentator says: 'You can't trust Jane's views on tax policy because she once evaded taxes.' This is an example of:
- Tu quoque
- Ad hominem (abusive) (Correct answer)
- Appeal to authority
- Red herring
Correct answer: Ad hominem (abusive)
Attacking the person's character rather than their argument is an abusive ad hominem.
Question 6: Which of the following is the strongest counter-argument to the claim that capital punishment deters murder?
- Capital punishment is morally wrong
- Some murderers are mentally ill
- States without capital punishment have similar or lower murder rates than those with it (Correct answer)
- The justice system sometimes convicts innocent people
Correct answer: States without capital punishment have similar or lower murder rates than those with it
Empirical evidence that murder rates do not differ by punishment regime directly undermines the deterrence claim.
Question 7: In evaluating an argument, an 'assumption' is best defined as:
- A premise explicitly stated in the argument
- An unstated premise the argument relies on to reach its conclusion (Correct answer)
- The conclusion of the argument
- A logical fallacy embedded in reasoning
Correct answer: An unstated premise the argument relies on to reach its conclusion
An assumption is an unstated premise that must be true for the argument's reasoning to hold.
LNAT Argument Evaluation 2
A politician argues: 'Crime rates fell after we increased police funding, so the funding caused the drop.' Which flaw best describes this reasoning?