Logical ReasoningDifficulty: Hard

PT155 S2 Q20 Explanation

Social observer: Advertising agencies

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

TopicsSufficient Assumption

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Stimulus

Social observer: Advertising agencies are willfully neglecting the most profitable segment of the market: older adults. Older adults control more of this nation’s personal disposable income than does the rest of the population combined. Therefore, advertising agencies gear their advertisements mainly to older adults.

What this question is testing

Sufficient Assumption

Your task

Find the assumption that, if added, guarantees the conclusion follows.

Common trap

Answers that only partly bridge the gap, leaving the conclusion unproven.

Winning move

Identify the new term in the conclusion and pick the choice that links it to the evidence.

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

The question
20.

Which one of the following, if assumed, would enable the conclusion of the social observer’s argument to

Answer choices

  1. Unrelated to Goal5% picked this

    Older people generally have larger incomes and have had longer to accumulate resources

    This doesn't have any language about "maximizing clients' profits", so it is functionally useless to us.

  2. Illegal Reversal / Opposite21% picked this

    No company can maximize its profits unless it markets its products primarily to a population segment that controls most of

    This says: max out profits → market mainly to [older people] But our conclusion is saying market mainly to [older people] → max out profits Unless = if it is not the case that. So one way to diagram this is, not marketing to won't population segment → maximize that controls most profits disposable income Our conclusion is the Opposite of that --- do market to will population segment → maximize that controls most profits disposable income (i.e. older people)

  3. Trap2% picked this

    Advertising that is directed toward the wealthiest people is the most effective means for a business to improve

    Unrelated to Goal Out of Scope = reputation This doesn't have any language about "maximizing clients' profits", so it is functionally useless to us. Also, the correct answer to Sufficient Assumption will not bring up any new ideas, such as "enhancing the reputation of products".

  4. Illegal Opposite17% picked this

    No advertising agency that tailors its advertisements mainly to an audience that does not control much of this nation’s personal disposable income

    This, like (B), is giving us an opposite/reversed version of the conclusion. It's saying: tailor ads mainly to segment of pop won't maximize that doesn't control → clients' profits much disposable income(i.e. not older adults) Meanwhile, this argument is saying, tailor ads mainly to segment of pop will maximize that does control → clients' profits much disposable income.(i.e. older adults)

  5. Correct55% picked this

    Any advertising agency that gears its advertisements mainly to a population segment that controls 50 percent or more of this nation’s personal disposable

    Why this is right

    We know that "older people" are a population segment that controls more than 50% of the nation's personal disposable income. There is another modern question (a Principle question about completing the space agency's current project, since the money we'd still have to spend on it is more than the money we've already spent) that uses this same mathematical rephrasing: if one chunk is bigger than the rest combined, then that first chunk is more than 1/2. Since older people control more than everyone else combined, they have more than half the disposable income. Pick any number for older people, make sure it's more than the combined total for non-older people, and you'll see why it's always more than half. Older people: 10 billion not older people: 9 billion nation's total: 19 billion (older people > 1/2) So since we know that this language of "pop segment that controls 50% or more" applies to "older people", this rule allows us to say that, If an ad agency gears its ads mainly to [older people], then it will maximize its clients' profits. Thus, we've derived the conclusion.

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

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