Diagram

[ManhattanPrepLSAT1]

Quoted from joshmercer80

This one threw me for a loop. I wasn't quite sure how to organize this game. Can anyone explain to me how they organized the information? When I got to the questions, I was totally unprepared. I tried a logic chain and an open board but neither really did the trick, or at least I didn't know how to translate conditions into visual references.

[giladedelman]

Thanks for the question! This is an interesting game.

The logic chain is tempting, but it's not really a binary grouping game. We do have two groups -- for and against -- but the constraints aren't the "If A is for, B is against" type.

Instead, we'll do best to diagram this game using the open board. Notice that we're not trying to figure out anything about whether the judges are conservative, moderate, or liberal; we know how many of each type there are. What we are interested in is whether they rule for or against the petition. In other words, we're trying to assign them to either "for" or "against."

I've attached the diagram I used to solve this game. Now that you know what type it is, why don't you give it a try, and get back to me if you still have questions?

[joshmercer80]

Thank you for the diagram. Once I had the set-up, I was able to answer all the questions correctly. I am however still struggling to hit the 8 minute mark for completing a logic game. I assume it just comes with practice and experience.

[ManhattanPrepLSAT1]

Honestly, that's exactly right.

I was only getting through 3 games during most of my initial LSAT prep period of 10 weeks. It wasn't until about 10 days before the LSAT that I started finishing all 4 games.

Just keep working on them, and always push yourself to move quickly and look for deductions.

[ManhattanPrepLSAT1]

walkerdoreen07 wrote:

This is a confusing game for me. I had question 13 right, but question 14 not sure why answer c is the answer.

The LM is throwing me off. silly question the two m's would be separate a(for and against) because of rule 1 contrapositve???

sorry to be all over the place.

my chart F A
LM CM

[giladedelman]

Thanks for the question!

So, why is (C) the correct answer? Why must it be true that at least one liberal voted for Datalog?

Well, if we try disproving it, we have to put all three liberals against Datalog. But wait: if all three liberals are against, then both conservatives have to be for. Since we know at least one conservative is against, this is impossible. We can't have all three liberals voting against, so there must be at least one voting for.

(Now that we know there must be at least one liberal voting for, we can go ahead and add that to our diagram.)

Does that answer your question? Let me know if you're having any other problems.

[interestedintacos]

This game is clearly not an assignment game by Manhattan's classifications, but it shows how useful the open board techniques can be in general. At least that's what I've found so far. Any diagramming technique that helps to even lessen the feeling (even if not necessarily the reality) of uncertainty is good in my book.

[staceyhursh]

Can someone walk me through question 16 on this one? I don't eve know where to begin and I got it wrong the first time I did it thinking I nailed it. Ugh.

[BenDaniel12]

Can someone walk me through question 16 on this one? I don't eve know where to begin and I got it wrong the first time I did it thinking I nailed it. Ugh.

Knowing there are only two judges voting against Datalog, one of those being a Conservative, there's only three templates possible. Once the templates are completed, what must be true can be determined from looking at what is the same across the three templates. After setting up the template with the Moderate in to vote as the other judge against Datalog, you'll probably see a key inference. Don't know if this is the most effective way.

I have a question regarding the first condition. I usually write out the contrapositives, and while I could note the contrapositive in formula form, I can't quite understand what it means.

[sukim764]

Can someone walk me through question 16 on this one? I don't eve know where to begin and I got it wrong the first time I did it thinking I nailed it. Ugh.

Knowing there are only two judges voting against Datalog, one of those being a Conservative, there's only three templates possible. Once the templates are completed, what must be true can be determined from looking at what is the same across the three templates. After setting up the template with the Moderate in to vote as the other judge against Datalog, you'll probably see a key inference. Don't know if this is the most effective way.

I have a question regarding the first condition. I usually write out the contrapositives, and while I could note the contrapositive in formula form, I can't quite understand what it means.

I believe there are only two possible diagrams for question #16: first: 1 conservative and 1 liberal being against, second: two conservatives against.

To staceyhursh:
The key to this question (my initial pick was B) really comes down to implementing the last rule in diagramming the two possible choices for the question. Lastly, don't forget that this question is a MBT--that's how I mistakenly choice B the first time.

[soyeonjeon]

I do not get 13, 14 and 16.

I do not understand the first rule, what would be the contrapositive of the first rule? I would assume that its contrapositive would be if the moderates voted differently from the two conservatives and at least one liberal. I would assume that the contrapositive of this rule would NOT be that if the two moderates did not vote the same way..then..bla.
But I might be wrong, which is why I am not able to solve 13 or 14 or 16.

For 14, I do not see how to solve it other than to try to disprove every answer choice as indicated in one of the comments.

For 16, I do not see how we get narrowed down to two possibilities as mentioned in one of the comments.

I really do not understand this problem in general and help would be highly appreciated.
Thanks in advance.

[timmydoeslsat]

I do not get 13, 14 and 16.

I do not understand the first rule, what would be the contrapositive of the first rule? I would assume that its contrapositive would be if the moderates voted differently from the two conservatives and at least one liberal. I would assume that the contrapositive of this rule would NOT be that if the two moderates did not vote the same way..then..bla.
But I might be wrong, which is why I am not able to solve 13 or 14 or 16.

You are closer than you think understanding the first rule.

CC and at least one L vote same way ---> MM votes same way with them

The contrapositive of the rule can be triggered by either scenario you mentioned. If it is not true that MM voted together, then you would trigger the contrapositive. There is no way that CC and at least 1 L votes the same way because this would force the two M's to be together.

So the contrapositive could be triggered simply by knowing that AT LEAST 1 M fails to vote with the CCL group. Both M's failing to do that will of course trigger it.

With both conditional rules in this game, simply knowing that the C's voted differently or the M's voted differently amongst its own group would be sufficient to know the contrapositive is triggered.

In other words, consider the LLL ---> CC votes opposite way rule.

If the C's vote differently from each other, then you are denying a requirement of all L's voting together.

For 14, I do not see how to solve it other than to try to disprove every answer choice as indicated in one of the comments.

For 16, I do not see how we get narrowed down to two possibilities as mentioned in one of the comments.

If you did not make the upfront inference about L in this game, then I would save a question like 14 for last so that previous work can do the work for us.

The fact that we are given that at least one C voted against should trigger your interest. What do we know if LLL votes the same way? No C votes that way. So could we have all L's votes against? Nope, we have a C there. So we know that at least one L must always vote for.

So for 16, we are given a fixed distribution for the 7 judges. 5 for, 2 against.

_ _ _ _ _ .... C _

We know that since we have LLL and MM...we know that at least 2 LL and 1 M will be in. There is only one slot left in the out column.

L L M _ _ .... C _

So we now have L M C left to place. We only have one rule left, which is the LLL ---> No C that way rule. The other rule, that is now void, was the CC and at least 1 L vote the same way rule. We know that this rule can never be triggered in this scenario.

So we can use the LLL rule in placing our last 3 variables. You could also use any of C, M, L in a "scenario of 2" situation. In other words, you have this below:

L L M _ _ .... C _

We know that we have CML left to place. We can pick any of those variables and have a situation of it voting for....then a situation of it voting against. This would show all of our possibilities. We must consider the LLL rule while doing that however. I will pick L to use in my scenario of 2.

L voting for:

L L M L M .... C C

L voting against:

L L M M C .... C L

As we can see, in either scenario, it must be true that both M's vote for.