LSAT Logic Reasoning 5

Question 1

A judge instructs: 'If new evidence is presented, the case will be reopened. The case was not reopened.' What can be concluded?

Accepted Answer

No new evidence was presented.

Answer

Applying modus tollens: the case was not reopened (consequent false), so no new evidence was presented (antecedent false).

Question 2

The argument 'We should legalize marijuana because prohibition has failed, just as alcohol prohibition failed in the 1920s' relies primarily on which reasoning technique?

Accepted Answer

Analogical reasoning between two historical cases.

Answer

The argument draws a parallel between two historical prohibition situations, inferring that what happened with alcohol will apply to marijuana.

Question 3

Which of the following, if true, most strengthens the argument that mandatory sentencing laws reduce violent crime?

Accepted Answer

Violent crime rates fell in states with mandatory sentencing but remained flat in comparable states without such laws.

Answer

A controlled comparison showing crime fell under mandatory sentencing but not without it provides direct causal evidence for the claim.

Question 4

A scientist argues: 'This new species must be carnivorous because it has sharp teeth, and all previously discovered members of its genus are carnivorous.' This is an example of:

Accepted Answer

An inductively strong argument whose conclusion is probable but not certain.

Answer

The conclusion is supported by genus-wide patterns and anatomical evidence, making it inductively strong but not deductively certain since exceptions are possible.

Question 5

Which flaw undermines the following argument: 'Students at elite universities earn higher salaries, so attending an elite university causes higher earnings'?

Accepted Answer

It ignores that high-earning students may self-select into elite universities.

Answer

If high-achieving, well-connected students disproportionately attend elite schools, the school may not be the cause of earnings — pre-existing traits may be.

LSAT - Law School Admission Test Practice Test

LSAT - Law School Admission Test Practice Test

LSAT Logic Reasoning 5