Q3

[walkerdoreen07]

hello,

I have a question on (S2, G1)Q3, I was between answer A and B, I understand why C is not the answer. Answers D and E could be true?


Thank you
Doreen

[aileenann]

Hi Doreen,

That's a great question. It's really important to know why incorrect answer choices are incorrect.

This question adds an additional condition (lentils last) and asks which must be true - that means that 4 of the answer choices need not be true. Before we jump into the answer choices, let's think about the ramifications of putting L last (by the way, you can see a diagram in Noah's posting in this thread: pt40-s2-g1-charlie-makes-a-soup-by-adding-exactly-six-t265.html).

If L goes last, we also know that Z does not go first (contrapositive of the conditional constraint about Z going first). An important non-inference is realizing that M doesn't have to go 3rd just because L goes last (looking at the first constraint) - if you didn't fall for this, great! If you did, make a mental note to pay more attention to trigger v. non-trigger parts of conditional statements.

So we still don't know too much as far as inferences go, but let's take a look at the answer choices you asked about specifically - (D) and (E), thinking about whether we can falsify them. If we can, they don't have to be true, and they are not our answer.

(D) is falsifiable; consider TZOMKL
(E) is also falsifiable; the above example TZOMKL shows this. (note that this shows the value of reusing potential combinations to disprove multiple answer choices).

You also said you were stuck between (A) and (B) so let's take a look at those.

(A) is another way of saying that Z can't be first - one of the few things we inferred at the start. This absolutely does have to be true - perfect!
(B) is falsifiable; consider KOMTZL.

I hope this helps. Please let me know if you have more questions about this one!

[nagipaul]

on question 3 I couldn't narrow it down and b looked right. I got fooled by c just because I was so lost. the constraints left a lot unanswered

[noah]

Hey there, I'm not too sure what your question is - if you're bemoaning a game, we agree, there are some tough ones out there. If you have a question, we're happy to help, but you're going to need to tell us which game you're talking about and ask a more specific question. I bet we've already started discussing your game - take a look at the forum for this preptest's logic games: preptest-40-june-2003-lsat-answers-explanations-lg-f35.html

[ManhattanPrepLSAT1]

Here's a setup for this game as well as a walk through for questions 3 and 5.

Let me know if you still need further help with this one!

[tsj215]

Hi

I'm having a hard time understanding your explanations.

So I get why choice c (my guess) is wrong. I didn't look closely at the trigger v non trigger. But what do u mean when you say d and e are falsifiable? I see u list a possible ordering after But the ordering you use after both isn't following the constraints of what d and e are saying.

[timmydoeslsat]

Hi

I'm having a hard time understanding your explanations.

So I get why choice c (my guess) is wrong. I didn't look closely at the trigger v non trigger. But what do u mean when you say d and e are falsifiable? I see u list a possible ordering after But the ordering you use after both isn't following the constraints of what d and e are saying.

This is my global diagram:



Question 3 is a local question that asks what must be true if L is last.

L being last will trigger the second rule. We know that L - O will not happen in this situation. How could L precede O if L is last? It cannot. This means the sufficient condition listed could never happen. This is what a contrapositive is. So we know Z will not be first. This is what must be true. (A) At least 1 variable will come prior to Z.

The rest of the answer choices are things that could be falsifiable. D and E are not considered constraints. If you can muster up a hypothetical that is consistent with the local rule given in this question stem and of the global rules of the game, AND it goes against what an answer choice says, then that answer choice is not something that must be true.

[Darabi.Shawn]

(D) is falsifiable; consider TZOMKL
(E) is also falsifiable; the above example TZOMKL shows this. (note that this shows the value of reusing potential combinations to disprove multiple answer choices).

Just wanted to clear things up because it was bothering me. but aren't the examples you gave invalid? In both of these scenarios K cannot go 5th. But in either one you can switch places with Z and M and your point would still prove valid.