PT 19 Section 2 #22

[jbud72]

Can someone explain to me how D parallels the stem in this question? What is sufficient and necessary in the stem?

[matt@atlaslsat]

This one you're not going to like. The argument is way more subtle and actually to some extent less interesting than a lot of these LR questions.

The argument gives us a conditional relationship, tells us that the sufficient condition has been met, and then concludes therefore that the necessary condition follows.

CG + GTE ---> SDP
CG + E
===========
SDP

(Notation Key: CG = congenial guests, GTE = good things to eat, SDP = successful dinner party, E = things to eat)

The flaw in the reasoning is that the sufficient condition has not actually been met. Having plenty to eat is not the same as having plenty of good things to eat. So the conclusion does not follow from the evidence as we have not established that Sylvia had plenty of good things to eat.

(A) is a valid argument and so does not match the flaw.
(B) is a reversal, so is flawed, but does not commit the same flaw.
(C) is a valid argument and so does not match the flaw.
(D) matches the flaw as we do not know that Arnold's meat stock was well-seasoned.
(E) is a negation, so is flawed, but does not commit the same flaw.

Does that clear this one up for you?

[jbud72]

Completely cleared it up. Thanks so much!