#6 - Local, Justify

[Dave Killoran]

Complete Question Explanation
(The complete setup for this game can be found here: lsat/viewtopic.php?t=7371)

The correct answer choice is (E)

The question stem creates a GP E H sequence, and then asks for a piece of information that will force a grade of E to be assigned. Thus, either the sequence has to be pushed to start at grade B (which would force history to receive an E), or one of the languages has to be added to the beginning or end of the sequence in order to force all five grades to be assigned. Answer choice (E) forces all five grades to be assigned by adding Russian to the end of the sequence, creating the sequence GP E H R.

[kalifaingold]

Hello, I am very confused by this question. I don't understand why E must be true, couldn't any addition to the sequence force one of his classes into the "E position"
Using a) as an example if he received a lower grade in Italian than economics couldn't the new sequence just be GP-E-I-H? Since we aren't told that E and H are consecutive, couldn't a letter fit in between them forcing H into a failing grade?
I understand your explanation and why E is correct but I just don't understand why others are incorrect.
Thanks

[Jeremy Press]

Hi Kali,

It's not enough in this question to add a grade into the middle of the sequence. That's because John could receive more than one of any individual grade. And, when you add a grade for Italian or Russian into the middle of the sequence, you have flexibility about where you put its pair (the other one of either Italian or Russian). The below diagrams for each of answers A through D reflect ways we can diagram the new information of the answer choice without assigning a failing grade (thus disproving those answer choices). Does that make sense?

Screen Shot 2020-01-27 at 12.55.26 PM.png

I hope this helps!

Jeremy

[Iceberg.Human]

Hi, I'm struggling to understand as to why 1) L/R cannot be in the middle of E-H sequence (which is already mentioned by Kali, but I still couldn't quite get it), 2) why do all grades need to be filled in? Since the neither question stem nor stimulus doesn't mention anything about John needs to have all the grades, I'm wondering where did the "in order to force all five grades to be assigned" (from explanation) is coming from. Could you help me understand with this? Thank you!

[Rachael Wilkenfeld]

Hi Iceberg,

I'm not sure what L stands for in your question. However, the reason R can't go in the middle is because we need it to extend the chain.

We want to know what would force John to receive a failing grade. We could do that in one of two different ways. We could have a rule that a certain grade is failing (for example, John receives an E in history), or we could have a rule that makes a chain long enough to force one class to be a failing grade. When we look at the answer choices for this question, they are helping to create a chain, not providing an absolute grade for any class.

Therefore, we need to think about what we could do to a chain to make it require a failing grade. Without knowing any position of any of the grades, the only way we could force a failing grade is if the chain is five grades long. That is, the chain has to include five separate grade levels, or it would allow for a series of grades that did not include a failing grade (for example, A-D). We need a sequence of five different grades to ensure that one grade will be an E.

Our rules and question already create a four grade sequence: GP E H. We are looking for an answer choice that puts something either in the front of that chain (pushing H into the failing slot) or at the end of the chain. Let's take a look at the answer choices.

Answer choice (a) could mean that IH have the same grade, and ER have the same grade. G could have an A, P a B, ER a C, and IH a D. No E grade is required here.

Answer choice (b) could use the exact same set up as answer choice (a). No E grade is required.

Answer choice (c) could have overlap with G and I, and P and R. GI could have an A, PR a B, E a C, and H a D. No E grade required here.

Answer choice (d) could look very similar to answer choice (a). G could have an A, P a B, EI a C, and HR a D. No E grade required.

Answer choice (e) is the only one that forces an extension of the chain by pinning something to the end of the chain. If R is a lower grade than H, we now have GP E H R. That would force a grade into the failing category. It's the only choice that is enough to force the grade of E in one class.

Hope that helps!
Rachael

[adriana180]

I think for me, I was trying to prove that the options could all be placed in E by simply moving the string to start at grade B. When the string is moved to start at B, option D is a possibility and E was not an possibility. So, knowing which strategy to use and exactly what the question is asking seem to be the keys.

[Jeff Wren]

Hi sincadriana,

Yes, the key to correctly answering this question is to first understand exactly what this question is asking us to do, which is to find an answer that forces at least one of the variables to receive a failing grade of "E" when combined with the additional "new" information given in the question (that John receives a lower grade in economics than physics) and the original rules of the game.

As mentioned above, when combined with the original rules, this new information creates a four variable chain GP - E - H in which each of these four variables must get a different grade (i.e. no overlap). Since we would need a five variable chain (meaning five variables that do not overlap, all receiving different grades) in order to guarantee that at least one subject got a failing grade of "E," we're looking for an answer that extends this chain either by adding a variable to the front of the chain (before G) or at the end of the chain (after H). Answer E does the second, by adding Russian after History.