Logical ReasoningDifficulty: Medium

PT133 S1 Q21 Explanation

On the Discount Phoneline

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsParallel

Keep going in LSAT Lab

  • Save & drill this skill — build targeted practice sets from questions like this one

  • Video walkthroughs — watch every question solved step by step

  • 81 official LSATs — as questions, timed sections & full-length tests

Start practicing free

Free to start

Full official LSAT questions are available through LawHub. This page provides LSAT Lab's explanation, strategy, and review tools without republishing the full official question.

Stimulus

On the Discount Phoneline, any domestic long-distance call starting between 9 A.M. and 5 P.M. costs 15 cents a minute, and any other domestic long-distance call costs 10 cents a minute. So any domestic long-distance call on the Discount a minute costs 15 cents a minute.

What this question is testing

Parallel

Your task

Break the argument into its conclusion and evidence, then do exactly what the question stem asks with that structure.

Common trap

Answers that sound relevant to the topic but don't connect to the argument's actual reasoning.

Winning move

Predict what a right answer must do, then test each choice against the conclusion-evidence gap.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
21.

The pattern of reasoning in which one of the following arguments is most similar to that in

Answer choices

  1. Bad Conclusion Match4% picked this

    If a university class involves extensive lab work, the class will be conducted in a laboratory; otherwise, it will be conducted in a normal

    The premises do establish that every class that involves lots of lab work will either be lab or normal classroom. A correct conclusion would have said "if a class with lots of lab work isn't lab, then it must be normal classroom" (or vice versa for lab/classroom) But instead, this conclusion is saying "if a class isn't one with lots of lab work". That would only match the original conclusion if the original had said "if a call that isn't domestic long distance doesn't cost 10 cents ..."

  2. Bad Conclusion Match11% picked this

    If a university class involves extensive lab work, the class will be conducted in a laboratory; otherwise, it will be conducted in a normal

    The premises do establish that every class that involves lots of lab work will either be lab or normal classroom. A correct conclusion would have said "if a class with lots of lab work isn't lab, then it must be normal classroom" (or vice versa for lab/classroom) But this conclusion doesn't mention the "extensive lab work". This would only match the original conclusion if the original had just said "So if any call doesn't cost 10 cents ...", but it was "So any domestic long-distance call that doesn't cost 10 cents".

  3. Bad Conclusion Match6% picked this

    If a university class involves extensive lab work, the class will be conducted in a laboratory; otherwise, it will be conducted in a normal

    This has the same problem as (B). The premises do establish that every class that involves lots of lab work will either be lab or normal classroom. A correct conclusion would have said "if a class with lots of lab work isn't lab, then it must be normal classroom" (or vice versa for lab/classroom) But this conclusion doesn't mention the "extensive lab work".

  4. Bad Conclusion Match5% picked this

    If a university class involves extensive lab work, the class will be conducted in a laboratory; otherwise, it will be conducted in a normal

    The premises do establish that every class that involves lots of lab work will either be lab or normal classroom. A correct conclusion would have said "if a class with lots of lab work isn't lab, then it must be normal classroom" (or vice versa for lab/classroom) But this conclusion says "If a class with lots of lab work, then not classroom." That would have been like if the original argument had said "If it's a domestic long-distance call, then it's not 10 cents" (or not 15 cents, same difference)

  5. Correct74% picked this

    If a university class involves extensive lab work, the class will be conducted in a laboratory; otherwise, it will be conducted in a normal

    Why this is right

    The premises establish that every class that involves lots of lab work will either be lab or normal classroom. Then the conclusion says, "so if a class with lots of lab work isn't X, then it must be Y".

    Skill tested: Parallel · how this choice captures the argument's function is the move to repeat next time.

Continue the review in LSAT Lab

Save this question, watch the video walkthrough, and drill similar questions in your LSAT Lab account.

Save and practice this skill
LSAT Lab

Turn this review into a targeted study plan.

Save this question, drill more like it, watch the video walkthrough, and track your progress in your LSAT Lab account.

Start practicing free