LSAT Explanation PT 20, S4, Q15: Rhonda will see the movie tomorrow

LSAT Question Stem

The pattern of reasoning displayed above is most closely paralleled in which one of the following? 

Logical Reasoning Question Type

This is a Parallel question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

This problem is a Parallel Reasoning question, which means we are looking for an answer choice that follows the same pattern of reasoning as the passage.

Let's first analyze the passage using formal logic notation:

1. R -> P (Rhonda sees the movie only if Paul goes to the concert)

2. P -> T (Paul goes to the concert only if Ted goes)

3. /T (Ted refuses to go to the concert)

Conclusion: /R (Rhonda will not see the movie)

Now let's analyze each answer choice:

a) Janice comes to visit -> Mary will not pay the bills tomorrow

Janice comes to visit -> Janice locates a babysitter

Janice has located a babysitter

Conclusion: Janice will visit Mary

This choice does not link the first element to the last and involves a Mistaken Reversal of the premise. It is not parallel to the passage's reasoning, so it is incorrect.

b) Gary does laundry -> Peter has to work

Peter has to work -> Cathy is ill

Cathy is not ill

Conclusion: Gary will not do his laundry

This choice can be diagrammed as:

G -> P -> C

/C -> /G

This choice involves a correct additive inverse and uses the contrapositive, just like the passage's reasoning. This is the correct answer.

c) Kelly barbecues fish -> (no rain and fresh trout)

No rain, but no fresh trout

Conclusion: Kelly will not barbecue fish

Since the first premise contains two sufficient conditions, this response fails the Premise Test and is incorrect.

d) Lisa attends reunion -> (Jared attends or Karl attends)

Karl does not attend, but Jared does

Conclusion: Lisa will attend the reunion

Since the first premise contains a choice of necessary elements, and the passage did not, this response fails the Premise Test and is incorrect.

e) George goes to the museum -> Mark agrees to go

Mark goes to the museum -> Mark postpones most appointments

Mark postpones some appointments

Conclusion: Mark will go to the museum

This response does not link the first and last elements and contains a Mistaken Reversal of the premise. This choice contains fallacious reasoning and is incorrect.

Therefore, the correct answer choice is (B), as it follows the same pattern of reasoning as the passage.