Q18

 
megm7267
Thanks Received: 0
Jackie Chiles
Jackie Chiles
 
Posts: 36
Joined: November 07th, 2010
 
 
 

Q18

by megm7267 Wed May 18, 2011 8:47 pm

This Q seems like it takes a long time to solve with the constraints. Is there a quick way of approaching it?
User avatar
 
noah
Thanks Received: 1192
Atticus Finch
Atticus Finch
 
Posts: 1541
Joined: February 11th, 2009
 
 
 

Re: Q18

by noah Thu May 19, 2011 12:10 pm

Yup - there's a pretty efficient way to solve this. First, let's interpret the new condition.

If P must be assigned to any subcommittee that F is assigned to, as well as any that G is assigned to, it seems that P must be the one that serves on all 3. If you're not convinced, try putting M on all 3 and then P with F and P with G - who's left? H and I, and they can't be together.

So, we've got P in all 3, with F and G a top two of them:
_ _ _
F G __
P P P
-- -- --

Now, who's left? We have to place H and I in different places, M and one more mystery character. So, this could look like this:

(H I M ?)
_ _ _
F G _
P P P
-- -- --


This should make it pretty easy to evaluate the answer choices:

(A) can't be true because if M is with F and G, then H and I are stuck together.

(B) can't be true - M could be with either H or I, but not with both. There's only one column that still has 2 available slots.

(C) is correct - H could be in the F and G subcommittees, leaving M and I together.

You'd pull the trigger at this point. But, for review's sake:

(D) can't work - we only have one mystery character, this would require two extra Fs (beyond the one that's already assigned)

(E) is similar to (D) - there aren't enough mystery characters for this option.

The key to solving this efficiently is to follow the inference chain and then show yourself "who's left" so that you can quickly evaluate the answer choices.

Does that help?
 
megm7267
Thanks Received: 0
Jackie Chiles
Jackie Chiles
 
Posts: 36
Joined: November 07th, 2010
 
 
 

Re: Q18

by megm7267 Mon May 23, 2011 2:40 pm

Yes thank you!

This solution really shows me how important flexibilty is in solving LGs
 
mkhan189
Thanks Received: 1
Vinny Gambini
Vinny Gambini
 
Posts: 6
Joined: June 21st, 2011
 
 
 

Re: Q18

by mkhan189 Tue Jun 19, 2012 4:00 pm

Practice book says answer is B! :(
But I looked it up online and the solution is C.. and I think Noah's explanation is right- so it should be C...
User avatar
 
noah
Thanks Received: 1192
Atticus Finch
Atticus Finch
 
Posts: 1541
Joined: February 11th, 2009
 
 
 

Re: Q18

by noah Tue Jun 19, 2012 5:39 pm

mkhan189 Wrote:Practice book says answer is B! :(
But I looked it up online and the solution is C.. and I think Noah's explanation is right- so it should be C...

ARGH!

Thanks for pointing that out. Nice job sticking to your guns.
User avatar
 
ManhattanPrepLSAT1
Thanks Received: 1909
Atticus Finch
Atticus Finch
 
Posts: 2851
Joined: October 07th, 2009
 
 
 

Re: Q18

by ManhattanPrepLSAT1 Mon Jun 03, 2013 4:45 pm