LG Substitution Questions

dustybottoms7
Posts: 83
Joined: Wed Oct 22, 2014 12:22 pm

LG Substitution Questions

Postby dustybottoms7 » Tue Nov 18, 2014 12:41 am

I've already worked through the PS Bible, taken roughly 25 PT's and drilled consistently but I have still have a tough time with substitution questions. These are the ones that state, "Which rule, if applied with all the other rules, constrains the game to the same extent as "x" rule?" I try and narrow them down upon observation, but I always end up having to try hypothetical after hypothetical to narrow my choices. Im averaging between -0 and -2 on most game sections now, but these questions are giving me the most trouble and eating up the most time. Any tips other than skipping and moving on until later? I'm really trying to perfect this section on the December test and do not want this type of question to screw me over. Thanks

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Bigfish41
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Joined: Thu Dec 19, 2013 4:52 pm

Re: LG Substitution Questions

Postby Bigfish41 » Tue Nov 18, 2014 1:05 am

These are tough for me as well, but I usually see how the rule specified to be substituted applies to the rest of the rules (the big picture,) then go through the answer choices.

hopeboaltberkeley
Posts: 168
Joined: Tue Jul 08, 2014 8:44 pm

Re: LG Substitution Questions

Postby hopeboaltberkeley » Tue Nov 18, 2014 4:23 am

I think the Manhattan LG guide dedicates some space to these. I'll look over it tomorrow again to confirm

hopeboaltberkeley
Posts: 168
Joined: Tue Jul 08, 2014 8:44 pm

Re: LG Substitution Questions

Postby hopeboaltberkeley » Tue Nov 18, 2014 4:41 am

but off of the top of my head, many of them seem way more daunting than they actually are. You'll often just have to look for the logically equivalent statement -- rather than some obscure rule that leads to the same effect in a really roundabout way.

So if a question asks "Which rule has the same effect as the rule that says X can't be in spots 6 and 7" the answer will often be something like "X cannot be placed later than spot 5." Not *that* easy, but something that doesn't need to be tested via hypotheticals. So sometimes just go down the line and look for the obvious one.

That doesn't always work, but it works for a surprising amount. I'll see what Manhattan says about the harder ones

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Dave Hall
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Joined: Thu Jul 28, 2011 4:18 pm

Re: LG Substitution Questions

Postby Dave Hall » Tue Nov 18, 2014 11:56 am

I take a two step approach, based on this principle: if the new rule is a substitute, then it must be the same as the old rule. It'll be true every time the old rule was true, and false every time the old rule is false.

1. Get rid of every answer choice that isn't true in every other bit of your prior work. If (A) wasn't true in you work for question 3, then it isn't true every time the old rule is true. It's not a substitute.

2. For any remaining choices, follow the new rule while making the old rule false. If (D) says "X must be before both Y and F", then place X before Y and F in your diagram, while at the same time creating a violation of the old rule. If you can follow the new rule while violating the old rule, then they are not the same. Such an answer is not a substitute.

Let me know if you'd like to see examples of this put into practice.




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