Logical ReasoningDifficulty: Medium

PT129 S3 Q17 Explanation

Consumer: If you buy a watch

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

TopicsNecessary Assumption

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Stimulus

Consumer: If you buy a watch at a department store and use it only in the way it was intended to be used, but the watch stops working the next day, then the department store will refund your money. So by this very reasonable standard, Bingham's Jewelry Store should give me a the watch I bought from them stopped working the very next day.

What this question is testing

Necessary Assumption

Your task

Find the assumption the argument requires in order for its conclusion to hold.

Common trap

Answers that would help the argument but aren't strictly required (sufficient, not necessary).

Winning move

Negate each choice — the right one breaks the argument when negated.

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

The question
17.

The consumer's argument relies on the

Answer choices

  1. Too Strong1% picked this

    one should not sell something unless one expects that it will function in the way it was

    Too Strong: conditional Out of Scope: "should not sell" This says, "If you don't expect something to function they way it was designed to, then you shouldn't sell it." This doesn't match up well at all with the argument. Our author is arguing, "If you sold me something that stopped functioning the next day, then you should give me a refund."

  2. Out of Scope Comparison13% picked this

    a watch bought at a department store and a watch bought at Bingham's Jewelry Store can both be expected to keep working for about

    Out of Scope Comparison: product life Too Strong: about same length of time The author isn't assuming anything about a quality / endurance comparison between department stores and Bingham's Jewelry store. The only comparison being assumed is that it would be reasonable to apply the department store's refund policy to Bingham's Jewelry store.

  3. Too Strong13% picked this

    a seller should refund the money that was paid for a product if the product does not perform as the

    Too Strong: conditional Out of Scope: purchaser's expectations We don't know if the author thinks that in every single case that a consumer had different expectations for how a product would perform that the seller should refund the money. The problem with the watch wasn't a gap between expectations and reality with how the product would perform. The product performed as the consumer expected, but then it stopped working the next day. To make this better match the argument, we would need to tweak the end of this answer choice to read, "... if the product stops performing the way the product is intended to perform".

  4. Correct72% picked this

    the consumer did not use the watch in a way contrary to the way it was

    Why this is right

    This just establishes that the consumer used the watch only as it was intended to be used, completing the other idea in the trigger of the rule that "if bought at store and used only as intended and watch stops working next day, then store will refund". If we negated this, it would turn into a big objection: "They shouldn't give you a refund. You did use the watch in a way contrary to the way it was intended to be used."

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

  5. Irrelevant Distinction: "new vs old"0% picked this

    the watch that was purchased from Bingham's Jewelry Store was not

    The rule cited has nothing to do with new vs. used watches. It just says "if you buy a watch," so we have no reason to think the author is assuming anything specific about new vs. used watches.

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