Reversal Answer Choices

[hyk1310]

Dear Lsat gurus,

A lot of answer choices have reversals (Mistakes sufficient condition for necessary condition).

Is there ever a situation where an answer choice reverses the order of the sufficient/necessary within the reversal, and therefore became a wrong answer?

For example, the stimulus in actually mistakens a necessary conditions for a sufficient condition, but an answer choice would say that the stimulus mistakened a sufficient condition for a necessary condition.

Also, since taking the contrapositives would yield that the reversal within the reversal to be identical, I was wondering if I had to pay attention to this.

I am asking because whenever I spot a reversal, I want to be able to go straight to the answer choice with the reversal without any hesitation.

I thank you for your help.

[ohthatpatrick]

Good question. No there's no difference between saying "the author confused the left side with the right side" vs. saying "the author confused the right side with the left side'.

So you don't have to worry whether it's Suff vs. Nec, rather than Nec. vs. Suff

(meanwhile, you DO need to worry whether the author goes from Part to Whole vs. from Whole to Part)

The only hijinx you can see with Nec/Suff Flaw is that there might be more than one conditional statement in the premise, and you need to make sure that the answer choice is saying the author bungled [the correct] one.

For example, take this symbolic argument.
If A, then B.
And if X, then B.

Thus, if X, then A.


Did the author mess up the first conditional or the second?




The second.
The author's conclusion is that
X -----------> A

We know that
X ---> B

The author's illegal move is thinking that
B ---> A

So there might be a trap answer that says
(A) author confuses a condition required by X with one that guarantees X

and a correct answer would say
(B) author confuses a something required by A with something that ensures A

Hope this helps.

[jakesodersten]

so interesting, thanks