PrepTest #30, LG #3 (Questions 11-16) Forum

[Anaconda]

It's an advanced linear problem (just read over the PS LG Bible regarding advanced linear today, and then attempted this problem) but it's giving me a lot of trouble. I don't know if I'm not making enough inferences, but my main struggle seems to be the car wash type variables.

I was okay with #11, but I can't answer any of the other questions

If someone could help me out and explain how to approach/map out the questions it would be very, very helpful.

Also, just for reference, is this an "easy," "normal," or "hard" advanced linear problem? I tried a few other and I at least got 4/5 or 4/7 (w/ silly mistakes) questions right, and only had major problems with the last question, so this LG is really kind of scaring me.

[Anaconda]

Okay, I figured it out (possibly)!

If you set the game up in two ways with M being in either 3 or 4, you get a few basic scenarios:

A) V T O M F or V F O M T, etc

B) V O T M F

Since what precedes M must be regular, Orlando is regular in scenarios A (whenever O is directly before M)

Since the cars washed 2 & 3 must be the same, and since M precedes T, O must also be regular.

So, I guess the trick here is to know that Orlando will always get a regular car wash.

The final question to the game if a sixth person, (Jabrohn) also gets a car wash, the only thing that CANNOT be true is the Orlando will get a premium car wash. I still am unsure about this though, since I don't think the answer could be that simple, afraid I got it "right" (on like my 4th try) based on pure luck.

Am I missing anything?

[zworykin]

If you set the game up in two ways with M being in either 3 or 4, you get a few basic scenarios:

A) V T O M F or V F O M T, etc
B) V O T M F

Second scenario in A is not valid, violates O-M-F.
The possibilities are:
VTOMF
VOTMF
VOMTF
VOMFT

So, yes, O is always either immediately before M or is in slot 2 and slot 3 is immediately before M, so either way it must be regular.

The final question to the game if a sixth person, (Jabrohn) also gets a car wash, the only thing that CANNOT be true is the Orlando will get a premium car wash. I still am unsure about this though, since I don't think the answer could be that simple, afraid I got it "right" (on like my 4th try) based on pure luck.

Am I missing anything?

There are a lot of new scenarios added because we have J, which is basically unconstrained. We can try eliminating answers:

B) Create hypo:
JVOTMF
RSSRRP
So, this could be true.
C) Create hypo:
VOTMFJ
RRRRSP
So, this could be true.
D) Create hypo:
VOMFTJ
PRRSSS
So, this could be true.
E) Create hypo:
The C and D hypos both fulfill this one.
So, this could be true.

Or, look at it this way. O still has to be after V, but before M and F. That means it has to be in slot 2 or 3 or 4. It can't be in 2 or 3 if it's premium, because there's only one premium. That leaves only slot 4, but if it's in 4, [MF] have to be 5-6, which would mean O is immediately before M and therefore is regular. So, even when we added J, O still can't be premium.