LNAT Logical Deduction 3 — Questions and Answers
Question 1: Either the witness is lying or the evidence was planted. The witness is telling the truth. What follows?
- The evidence was planted (Correct answer)
- The witness is unreliable
- The defendant is innocent
- The case is dismissed
Correct answer: The evidence was planted
In a disjunction, if one option is false, the other must be true; so if the witness is not lying, the evidence was planted.
Question 2: All felonies carry imprisonment. This offence does not carry imprisonment. Therefore:
- This offence is a misdemeanour
- This offence is not a felony (Correct answer)
- This offence carries a fine
- This offence is serious
Correct answer: This offence is not a felony
By contrapositive: if not imprisoned, then not a felony — the offence is not a felony.
Question 3: Most lawyers earn more than teachers. James is a lawyer. Which is the most logically warranted conclusion?
- James earns more than all teachers
- James probably earns more than most teachers (Correct answer)
- James definitely earns more than teachers
- James earns more than doctors
Correct answer: James probably earns more than most teachers
Since most (not all) lawyers earn more, James is probably in that majority but it is not certain.
Question 4: Passage: 'Speed cameras reduce accidents only where drivers know they are installed.' Which scenario most weakens this claim?
- A known camera site sees a 40% accident drop
- An unmarked camera site sees a 35% accident drop (Correct answer)
- Drivers slow down near visible cameras
- Public awareness campaigns also reduce accidents
Correct answer: An unmarked camera site sees a 35% accident drop
An unmarked camera reducing accidents contradicts the claim that awareness is necessary for the effect.
Question 5: If the statute is ambiguous, the court applies the literal rule. The statute is clear. What can be concluded?
- The court applies the literal rule
- The court does not apply the literal rule
- The court applies the purposive rule
- Nothing can be concluded about which rule applies (Correct answer)
Correct answer: Nothing can be concluded about which rule applies
The conditional tells us what happens when the statute IS ambiguous; it says nothing about what happens when it is clear.
Question 6: Five suspects — A, B, C, D, E — are ranked by likelihood of guilt. C is more likely than D. B is less likely than E. A is more likely than B but less likely than C. Which is the correct order from most to least likely?
- C, A, B, D, E
- C, A, E, B, D (Correct answer)
- C, D, A, B, E
- E, C, A, B, D
Correct answer: C, A, E, B, D
C > D; E > B; C > A > B gives C > A > B with E > B, and C > D; combining: C, A, E, B, D is consistent.
Question 7: Argument: 'Jury trials are expensive; therefore they should be abolished.' Which flaw does this argument commit?
- False dichotomy
- Non sequitur — cost alone does not justify abolition (Correct answer)
- Ad hominem attack
- Circular reasoning
Correct answer: Non sequitur — cost alone does not justify abolition
The conclusion (abolition) does not follow from cost alone without additional premises linking cost to abolition.
LNAT Logical Deduction 3
Either the witness is lying or the evidence was planted.
The witness is telling the truth.
What follows?