#22 - Local, Must Be True

[Dave Killoran]

Complete Question Explanation
(The complete setup for this game can be found here: lsat/viewtopic.php?t=2416)

The correct answer choice is (D)

If Cindy and Fran are the only two people on one of the planes, it follows that Dave cannot fly with Cindy, and thus Dave must fly with Bob. Accordingly answer choice (D) is correct.

[Nsaramouni]

Hello,

Why is it that Dave must fly with Bob, but not Ed must fly with Anna?

In my setup, I recognize that D and C cannot be paired, and I also see that E could potentially be with D but does not have to be as well. However, I cannot seem to determine why A/E are not a must pair. Can you please provide a little guidance?

Thank you kindly.

Best,
Nicholas

[KelseyWoods]

Hi Nicholas!

Careful with this game because it's a little tricky--it never actually specifies how many people are on a plane, so we can't assume that every plane gets one pilot and one co-pilot. We know from the second rule that every plane flying in the show has a pilot on board. But that doesn't mean that every plane flying in the show has a co-pilot. And some planes could have more than one co-pilot or pilot.

If C and F are the only people in one of the planes, then we know That D is on a plane with B and not A. But does that mean that E has to be on a plane with A? Not necessarily! E could be on the same plane with D and B and A could be flying solo.

Hope this helps!

Best,
Kelsey

[Nsaramouni]

Thank you!

[Taisiya]

Hello,
Going off of the similar question about the fact that D needs to fly with B, and so why not E needing to fly with A, I take it that the former takes priority because D needs to be on a plane. My question is - how do we know that? I know that the last rule states where Dave is able to fly (and not fly, as an inference), but it doesn't infer that D absolutely must be on a plane, does it? If it does, please point me in the direction of how I can recognize this, since I don't see it as of now:) So far, I have been reading it like so, "When D is present, D can only go here and here, but that doesn't necessarily mean D must be on a plane." Please help me! Thank you:)

[Ryan Twomey]

Hey Taisiya,

Everyone needs to be on a plane, but there can be more than two people on a plane. So we know D has to be on a plane just like we know A, B, C, E, and F have to be on planes. But in this question, when they say C and F are the only people on one of the planes, we know no one else can be on that plane.

So who can D fly with? We know D has to fly with a pilot, because every plane needs a pilot. D cannot fly with A in every question, but now D cannot fly with F in this question. So D must fly with B.

Now why does E not have to fly with A.... E could fly with D and B with three people on a plane and then A could fly alone because A is a pilot and copilots are not required for a plane to take off even though they must be used during the game at some point. So E does not have to fly with A for that reason.

I really hope this helps. In my opinion, this is one of the hardest games in the history of the LSAT. The key to understanding this game is that you are allowed to fly on a plane with more than 2 people, and also that we do not need to fly each of the 4 planes. Actually, the max number of planes we can fly is 3 and the minimum number of planes we can fly is 2. Another key point is that a plane can take off with just one pilot and that a copilot is not required for takeoff.

Good luck Studying!

Best,
Ryan

[Taisiya]

Dear Ryan,



First of all, thank you SO MUCH for your thorough elaboration - I'm sure many others will find that just as helpful as I did.


"Everyone needs to be on a plane" - that is an even better statement that pertains to my original question. Here we go: the concept that co-pilots are not necessities, while Pilots are, makes complete sense. With that in mind, where do I derive from the logic game that everyone does need to be on a plane? I'm obviously making this hard on myself, but I still cannot see where that is. The question mentions that the Planes are "available" to fly in the air show and that the "Pilots" are "all aboard planes that are flying in the show". I assumed that if only two planes were flying in the show, not everyone being ABCdef need to be on them. Is the "all aboard" the key to seeing that everyone is going to be involved in the show? Don't laugh - I just keep seeing that ABCdef are just as available to fly as Planes 1234 are available (vs. being mandatory), so either the key is in "all aboard" and I misread it, or I need to move back my LSAT date wayyyy back. Please let me know if "all aboard" is the key here (or what else is:) Sorry about how hectic I'm making this, but I appreciate you dissecting everything the way you did! The question didn't seem as hard for me (which I'm happy to hear/read it's a hard logic game), but I definitely don't want to be my own enemy in misreading or over-reading a question, so your explanations are perfect to help tailor our (students') learning processes:) Thank you!

In regards to this specific question (being question 22), I got it correct thanks to another method that you're more than welcome to comment (or critique) if you'd like - otherwise, I hope it's ok to share on here with others as well:) Before I jump into what that method was, I just want to clarify that the way I keep reading into this question, (specifically, the mandatory participation of all pilots and all co-pilots), is what I know would throw me off had the question 22 been asking a different kind of direction. So, although I was able to get the correct answer with the method following, I am not clear on a very important concept (that everyone must fly) that could've played a bigger role in this game, so I hope it's ok to seek even more of your guidance on that, as I mentioned earlier in this post. Thank you:)


Question 22:
what helped me get was to take the four plane placeholders (___ ___ ___ ___) and treat them as planes with no specific order. In one, we have "Cf"
In another we have "A"
In another we have "d"
(I kept my variables, being the Pilots & co-pilots as Upper-case and lower-case letters in my diagram, which was helpful, respectively: so ABC as Pilots and def as co-pilots).

Since "d" is a co-pilot, it needs a "Pilot", either "ABC".
"A" and "d" never fly together. So it can't be "A".
"C" could've worked....had the question SPECIFICALLY not said that "C" and "f" are the ONLY ones in their one plane.
All we have left is "Bd".

If we look back at the variables we are working with "ABCdef", only "e" isn't assigned, per the visual below.

_Cf_ _Bd_ _A__ ___

"e" can be assigned to either "A" or "Bd", but not "Cf". Therefore, since "e" doesn't have to be with "Bd" and doesn't have to be with "A", we can't use "e" in the answers since question is a Must Be True, while "e"'s assignment in this case would be a Could Be True.

Doing this visual with all four planes and crossing out the variables and actually demonstrating that e can go either way, and it's bound to go with A, the same way that B is with d, I was able to see the prominent role of "must" be true in the question to the answers.


I'm new on here and I imagine a student's input on their method of solving something may be unorthodox - please do share with me if my gut feeling is correct and I will refrain from deviating from the traditions of your forums in the future - I only wished to help paint a more in-depth picture that someone might see the use in as well! This is a blown-out reiteration of Kelsey and Ryan's responses (above mine), but in case anyone else is having a hard time connecting the dots to the capacity that I did (pardon, I was coffee-less in the process, with a Golden Girls episode in the background) you're welcome to see the visual that helped me find the right answer in seconds!:D

[Taisiya]

Dear Ryan,



First of all, thank you SO MUCH for your thorough elaboration - I'm sure many others will find that just as helpful as I did.


"Everyone needs to be on a plane" - that is an even better statement that pertains to my original question. Here we go: the concept that co-pilots are not necessities, while Pilots are, makes complete sense. With that in mind, where do I derive from the logic game that everyone does need to be on a plane? I'm obviously making this hard on myself, but I still cannot see where that is. The question mentions that the Planes are "available" to fly in the air show and that the "Pilots" are "all aboard planes that are flying in the show". I assumed that if only two planes were flying in the show, not everyone being ABCdef need to be on them. Is the "all aboard" the key to seeing that everyone is going to be involved in the show? Don't laugh - I just keep seeing that ABCdef are just as available to fly as Planes 1234 are available (vs. being mandatory), so either the key is in "all aboard" and I misread it, or I need to move back my LSAT date wayyyy back. Please let me know if "all aboard" is the key here (or what else is:) Sorry about how hectic I'm making this, but I appreciate you dissecting everything the way you did! The question didn't seem as hard for me (which I'm happy to hear/read it's a hard logic game), but I definitely don't want to be my own enemy in misreading or over-reading a question, so your explanations are perfect to help tailor our (students') learning processes:) Thank you!

In regards to this specific question (being question 22), I got it correct thanks to another method that you're more than welcome to comment (or critique) if you'd like - otherwise, I hope it's ok to share on here with others as well:) Before I jump into what that method was, I just want to clarify that the way I keep reading into this question, (specifically, the mandatory participation of all pilots and all co-pilots), is what I know would throw me off had the question 22 been asking a different kind of direction. So, although I was able to get the correct answer with the method following, I am not clear on a very important concept (that everyone must fly) that could've played a bigger role in this game, so I hope it's ok to seek even more of your guidance on that, as I mentioned earlier in this post. Thank you:)


Question 22:
what helped me get was to take the four plane placeholders (___ ___ ___ ___) and treat them as planes with no specific order. In one, we have "Cf"
In another we have "A"
In another we have "d"
(I kept my variables, being the Pilots & co-pilots as Upper-case and lower-case letters in my diagram, which was helpful, respectively: so ABC as Pilots and def as co-pilots).

Since "d" is a co-pilot, it needs a "Pilot", either "ABC".
"A" and "d" never fly together. So it can't be "A".
"C" could've worked....had the question SPECIFICALLY not said that "C" and "f" are the ONLY ones in their one plane.
All we have left is "Bd".

If we look back at the variables we are working with "ABCdef", only "e" isn't assigned, per the visual below.

_Cf_ _Bd_ _A__ ___

"e" can be assigned to either "A" or "Bd", but not "Cf". Therefore, since "e" doesn't have to be with "Bd" and doesn't have to be with "A", we can't use "e" in the answers since question is a Must Be True, while "e"'s assignment in this case would be a Could Be True.

Doing this visual with all four planes and crossing out the variables and actually demonstrating that e can go either way, and it's not bound to go with A, while B is bound with d (or else d can't fly at all), I was able to see the prominent role of "must" be true in the question to the answers.


I'm new on here and I imagine a student's input on their method of solving something may be unorthodox - please do share with me if my gut feeling is correct and I will refrain from deviating from the traditions of your forums in the future - I only wished to help paint a more in-depth picture that someone might see the use in as well! This is a blown-out reiteration of Kelsey and Ryan's responses (above mine), but in case anyone else is having a hard time connecting the dots to the capacity that I did (pardon, I was coffee-less in the process, with a Golden Girls episode in the background) you're welcome to see the visual that helped me find the right answer in seconds!:D

[Jeremy Press]

Hi Taisiya,

Your diagram of, and thought process regarding, question 22 is great. Nice work!

As to your specific question, as you suspected (again, nice work!) the answer is found in the language "all are aboard planes that are flying." Contrast that with the first sentence of the scenario: "Planes 1, 2, 3, and 4 - and no others - are available to fly in an air show." The planes are available, but that doesn't mean they necessarily fly in the show. So some planes might not be used in specific solutions. But the copilots are all aboard planes that are flying. So they have to be included in any determination of the people included in the show.

I hope this helps!

Jeremy

[Taisiya]

Dear Jeremy,


Thank you so much for bearing with me through that long explanation on my part and clarifying if I'm on the right track. All of you are just amazing - what would we all do without this forum? I hope you win the freaking lottery:D


Have a great day!