Q13

[kmewmewblue]

I am lost....

HELP please.

[timmydoeslsat]

Ok, so this question is asking us which one of these variables could you plug in, along with Russian, and have the entire selection of classes figured out.

Here is my set up of the game overall:



We need to go through the answer choices, plugging in each variable with R (Russian) and see if it allows us to fill out the four classes to be selected.



I know that when I have W in, I must have G out. So I have W and R in. I only have two left to place.

I also know that I do not have S9 or P due to the chain I created in my setup of rules.



This leaves me with 3 variables left to place: J, M, S3

I know that one of J and M must be out, and since that is the case, all of the "out" slots are filled. However we left with a dual option of J and M in and S3 being in. Nothing is certain and forces our hand. This is not our answer.

Answer choice B is something that I looked at and decided to not test it yet. It is vague in the fact that it simply says Statistics. I know that S3 is unlikely to force our hand in any significant way, and I am looking at S9 in the rules and I am frankly not seeing a lot of potential. I will not cross it out, but I will choose when to do my hypotheticals wisely.

Choice C gives us P.

So we know we have P and R. We have two slots left to fill.



We know that when we have P, we have S9 and we do not have W. We know that when W is out, G must be in because one of G/W is in and one is out. Thus, the scenario is played out for us. This is our answer.

[d.andrew.chen]

This might be dangerous in some situations, but instead of doing the potential answers in order, I attacked the problem by first stepping back and looking at the answer choices. Picking between W and G was especially notable to me...one has to be picked and R has no implication on either. Picking W would help solve that, as that would eliminate G. However, not having W is only necessary to stat at 9 AM, which is a "weak" variable in this sense b/c it says nothing about 3 PM. There was no G in the answer choices.

The only other variable that directly implicates W/G is Psychology...picking Psychology would take out W and require S...that gives us the necessary 3 courses of P S9 G just from that. Problem took less than thirty seconds with this method.

[ccheng]

I'd like to share my thoughts on how I approach this question.

As Manhattan LSAT has taught us, we should pay attention to element(s) that have most impact. These elements usually come in handy for tough questions like "determining maximum/minimum number of elements selected" or "fully determined".

By looking at the master diagram, we notice that when P is selected, it will cause a chain reaction. So P will definitely be worth considering when you are stuck.

For this question, I would start with P first. When P is selected besides R, S9 has to be selected and then W is out. W and G are bi-directional, so G has to be selected. With just one try, we got 4 courses (R, P, S9 and G). So (C) is the answer.

Hope this helps.