LG -- Substituting conditions with the same effect? Forum

[Mr.Binks]

Evening all,

I am wondering if anyone has an effective and efficient way of approaching the LG questions that ask you to substitute an initial condition with one that would produce the same effects?

I seem to consistently get bogged down by these questions because the only approach I can think of is creating hypotheticals with the answer choices, and this inherently takes quite a bit of time, especially if it is in the later games where time is a concern already.

Anyway, thanks for all your help in advance!

[emkay625]

This might be common sense, but generally speaking it seems they only ask about rules that have a big deduction associated with them or impact entities not mentioned in that rule. I look through the choices and am usually able to eliminate 3 to 4 choices because it's very easy to tell they won't lead to the same deduction.

[Mr.Binks]

This might be common sense, but generally speaking it seems they only ask about rules that have a big deduction associated with them or impact entities not mentioned in that rule. I look through the choices and am usually able to eliminate 3 to 4 choices because it's very easy to tell they won't lead to the same deduction.

I agree. On some of the ones I have encountered, I have immediately been able to eliminate 3 or so answer choices, but cannot seem to quickly narrow down the last two. I was wondering (hoping, perhaps) if there was a systematic approach to these question types or something of the sort.

[barneytrouble]

Well personally, I generally get through every LG game with more than enough time so I like to write out hypotheticals for just about every question. I know that my hypotheticals completely conform to the rules of the game, and TCR on these will not invalidate a single hypothetical, so when I encounter a rule substitution question, I apply answer choice A to my hypotheticals until it doesn't work on one. If it doesn't work on one, cross it out. Same for B, C, D and E. This pretty much always gets rid of 3 choices (and occasionally 4) super quickly and is fail proof.

[emkay625]

Well personally, I generally get through every LG game with more than enough time so I like to write out hypotheticals for just about every question. I know that my hypotheticals completely conform to the rules of the game, and TCR on these will not invalidate a single hypothetical, so when I encounter a rule substitution question, I apply answer choice A to my hypotheticals until it doesn't work on one. If it doesn't work on one, cross it out. Same for B, C, D and E. This pretty much always gets rid of 3 choices (and occasionally 4) super quickly and is fail proof.

+1 to this. I use the hypos for my previous questions to eliminate any remaining answer choices.

[Manhattan LSAT Noah]

We wrote a paper on this question type when it started showing up regularly.

Go to this page: http://www.manhattanlsat.com/training-center.cfm

And scroll down to "Rule Equivalency Bonus Chapter"

I hope that helps.

[Mr.Binks]

Thanks, Noah. Very helpful!

[ExcelBaller]

first, dont freak out when you see one. second, just write a little conditional chain (x->y) out to the side of each answer, compare it to the original rule and rules contrapositive. pick the answer that matches.

[SanDiegoJake]

Well personally, I generally get through every LG game with more than enough time so I like to write out hypotheticals for just about every question. I know that my hypotheticals completely conform to the rules of the game, and TCR on these will not invalidate a single hypothetical, so when I encounter a rule substitution question, I apply answer choice A to my hypotheticals until it doesn't work on one. If it doesn't work on one, cross it out. Same for B, C, D and E. This pretty much always gets rid of 3 choices (and occasionally 4) super quickly and is fail proof.

+1 to this. I use the hypos for my previous questions to eliminate any remaining answer choices.

+2. I like this method the best. Also, keep in mind that the new rule can't do any more or any less than the original. So if an answer choice doesn't do enough, it's eliminated. If it does too much, also eliminated.