## PT 22 S4 Q21

Prepare for the LSAT or discuss it with others in this forum.
d0rklord

Posts: 191
Joined: Sun Aug 21, 2011 3:31 pm

### PT 22 S4 Q21

DAMN YOU STUPID QUESTION. I HATE YOU.

What type of evil question is this? It's the way the stupid stupid answers are worded that take me FOREVER to do it..!!!!!!!!!

Clearly, I am frustrated.

Any help deciphering annoying ass confusing stupid shitfuck jargon would be appreciated

*deep breath*

Thanks you

VasaVasori

Posts: 571
Joined: Sun Dec 11, 2011 2:36 pm

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Last edited by VasaVasori on Sat May 02, 2015 10:58 pm, edited 1 time in total.

d0rklord

Posts: 191
Joined: Sun Aug 21, 2011 3:31 pm

### Re: PT 22 S4 Q21

I get the necessary/sufficient well enough (not perfect, but working on it)... It's the way they word all of the answers almost identical and annoyingly confusing that pisses me off. I got the questions right, but I would be lying if I didn't say it might've been luck... wahhh... I get sooo intimidated by the answers...

timmydoeslsat

Posts: 148
Joined: Wed Aug 03, 2011 2:07 pm

### Re: PT 22 S4 Q21

Yeah this is a lot going on here. I think this is one you would want to diagram out.

Terry:
AB some FC
AG ---> FC
__________
AB some AG

Pat:
AG some ~FC
AB ---> ~FC
___________
AB some AG

Both Terry and Pat are taking the necessary conditions of each respective conditional in their argument as a sufficient condition to reach their conclusions.

For instance, take Pat's argument:

AG some ~FC
AB ---> ~FC
___________
AB some AG

In this situation, our quantifying statement is going to be on the right hand side (necessary side) and we cannot conclude a some statement from this.

This is Pat's argument as one combined premise:

AB ---> ~FC some AG

To be able to conclude from this premise that AB some AG, Pat is mistakenly going from right to left with our arrow.

Notice the difference between what is an incorrect inference and a correct inference with some statements:

No inference can be derived: X ---> Y some Z

An inference can be derived: X some Y ---> Z

The quantifying statement is on our sufficient side of the arrow. We know that some X's are Y's. We know that every single Y is a Z. So we do know that some X's will be Z's.

The statement concerning the "no inference can be derived" is telling us that every single X is a Y. We know that some Y's are Z's. What if there is 1 X in the world, 5 Y's in the world, and 2 Z's in the world.

X
YYYYY
......ZZ

This shows that it does not have to be true that some X's are Z's. We can have that not be true. The Z's that are available can be with the Y's that do not have to be X's.

You will be able to motor through problems like this once you have a monster grasp on conditional logic.

d0rklord

Posts: 191
Joined: Sun Aug 21, 2011 3:31 pm

### Re: PT 22 S4 Q21

timmydoeslsat wrote:Yeah this is a lot going on here. I think this is one you would want to diagram out.

Terry:
AB some FC
AG ---> FC
__________
AB some AG

Pat:
AG some ~FC
AB ---> ~FC
___________
AB some AG

Both Terry and Pat are taking the necessary conditions of each respective conditional in their argument as a sufficient condition to reach their conclusions.

For instance, take Pat's argument:

AG some ~FC
AB ---> ~FC
___________
AB some AG

In this situation, our quantifying statement is going to be on the right hand side (necessary side) and we cannot conclude a some statement from this.

This is Pat's argument as one combined premise:

AB ---> ~FC some AG

To be able to conclude from this premise that AB some AG, Pat is mistakenly going from right to left with our arrow.

Notice the difference between what is an incorrect inference and a correct inference with some statements:

No inference can be derived: X ---> Y some Z

An inference can be derived: X some Y ---> Z

The quantifying statement is on our sufficient side of the arrow. We know that some X's are Y's. We know that every single Y is a Z. So we do know that some X's will be Z's.

The statement concerning the "no inference can be derived" is telling us that every single X is a Y. We know that some Y's are Z's. What if there is 1 X in the world, 5 Y's in the world, and 2 Z's in the world.

X
YYYYY
......ZZ

This shows that it does not have to be true that some X's are Z's. We can have that not be true. The Z's that are available can be with the Y's that do not have to be X's.

You will be able to motor through problems like this once you have a monster grasp on conditional logic.

Oi vey.. Thank you. I got the problem right, but I timed myself, and it took me nearly FOUR MINUTES!!!!! Cannot be the case on game day. Is it safe to say most questions with answer choices like this require the use of conditional logic? I grasp the concepts... but for whatever reason I can never tell where to apply them