Logical Reasoning

PT148 · S4 · Q20 At Tromen University this semester

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

  • 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

At Tromen University this semester, some students taking French Literature 205 are also taking Biology 218.

Conclusion

Some students taking French Literature 205 are not French Literature majors.

Evidence

Some students taking French Literature 205 are also taking Biology 218.

Every student taking Biology 218 is a bio major.

Evaluate

This is a weird argument, since the Bio class kind of comes in out of left field, so it's hard to think about how we're going to use that fact to prove our conclusion, that some people are not French-Lit majors.

We should start by focusing on the parallel between the first premise and the conclusion.

Conclusion: some French Literature 205 are not French Literature majors. Premise: Some French Literature 205 are in Biology 218.

We can see from this that our logic job is to get from .

We know one fact about being in Biology 218: .

So we really need to close the gap between . (that may seem like a self-justifying truth, but maybe you can be more than one major).

Goal

Since we have this Some French Literature 206 → Biology 218 Biology 218 → ~Biology major If we added this ~Biology → ~French Literature major major We could derive this Some French Literature 206 → ~French Literature major

But they might also give it to us in a more conversational style, like "At Tromen University, there are no double-majors."

20.

The conclusion drawn above follows logically if which one of the following is assumed to be true at Tromen University?

  1. French Literature 205 is a

    Out of Scope: required course

    We don't want new ideas in Sufficient Assumption answers. We just want them to patch up the existing ideas. Learning that French Literature 205 is required for French Literature majors wouldn't help us in any way to prove that certain people aren't French Literature majors.

    3% picked this

  2. Only biology majors are allowed

    Already Know This

    It's incredibly rare that this happens, but this answer basically restates a premise. This is technically still distinct, because this is a timeless rule. The premise was about the students who are currently taking Biology 218, but conditionally they're going to look the same: Biology 218 ? Biology major

    17% picked this

  3. There are more biology majors

    Out of Scope: more

    The total quantity of Biology vs. French Literature majors is irrelevant to us. It wouldn't make any difference if Biology had more / less / the same. This won't help us prove that some French Literature 205 students aren't French Literature majors. We already know that they're Biology majors. We just need to know if they could also be French Literature majors. There could be some students who are double majors (Biology and French Literature), whether there are more Biology, same Biology, or less Biology students overall.

    5% picked this

  4. There are more French-literature majors

    Out of Scope: more

    The total quantity of Biology vs. French Literature majors is irrelevant to us. It wouldn't make any difference if French Literature had more / less / the same. This won't help us prove that some French Literature 205 students aren't French Literature majors. We already know that they're Biology majors. We just need to know if they could also be French Literature majors. There could be some students who are double majors (Biology and French Literature), whether there are more French Literature, same French Literature, or less French Literature students overall. So this fact doesn't help us assess the critical vulnerability of the argument: is it possible these bio majors taking French Literature 205 are also French Literature majors?

    1% picked this

  5. Correct

    It is not possible to

    Why this is right

    As we predicted, we needed to get from "we know these some students are bio majors" to "we want to prove that these some students are not French literature majors". This rule clearly justifies that move. It also matches the missing conditional link we sketched out in the setup: Biology major ? ~French literature major

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

    74% picked this

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