Q26 - Marion knows that the bridge

[jlz1202]

By elimination I narrow down the answer to (D) but I am really confused by:
(1) how to diagram the conditional reasoning in the stimulus? (is there a two-layer reasoning by both "unless" and "can get to work only by leaving at least 45 minutes early"?) I always stuck in diagraming this kind of conditional reasoning.

(2) after spending long time on how to diagram the sentence, I am surprised to find out that picking out the correct answer in the question does not rely on understanding the reasoning at all--all it concerns is actually the last sentence--although marion hates taking train, she could take train if necessary.

So my question is: during real test, if confronting questions testing in this way, how could one know in advance what it's going to test and quickly pick the answer, avoiding tangled in the convoluted sentence?

[maryadkins]

Fantastic question.

Unless it's immediately apparent to you how to diagram this conditionally, don't waste time sweating it. Figure out what you do know/understand, and look for the flaw. If you can spot the flaw--which you could in this case--look for it in the answer choices.

One way to get to the conditional logic here conceptually is to ask yourself: if she's on time, what had to have happened? She either left early or took the train.

On time --> left early/took train

These are the only ways she can be on time. It's definitely a beastly mash-up of "unless" and "only ifs" that isn't really approachable in a "here's your rule" kind of way under the circumstances. But if you can step back and ask yourself, "What do I KNOW has to be true here if something else happens?," it may pop out at you.

[jlz1202]

Thanks for help!

[coco.wu1993]

Could anyone help explain why D is the right answer?

[ohthatpatrick]

Question Type: Flaw

Argument Core:

Conclusion:
Marion cannot avoid being late for work
..... (yikes, that's extreme ... CANNOT? Why is the author so convinced)

Prem:
If she doesn't take train --> getting to work on time requires leaving 45 minutes early.

But, she's gotta go to the bank before work, and the bank won't be open if she leaves 45 minutes early.

======
So that's why she can't get to work on time! Wait ... what? What about the train option? Take the train!

Oh, I forgot, there's a premise that says that Marion hates taking the train.

Okay, well, who cares? Life's hard sometimes, Marion. Go to the bank and then take the train if you wanna get to work on time.

=====

The way I'm summarizing things may sound overly conversational, but for many arguments that's the easiest way to understand them. I engineer my thinking (no train pun intended) around the Anti-Conc.

If the Conclusion is some extreme, certain belief that she CANNOT get to work on time, then LSAT has definitely left some door open that allows us to argue that she COULD get to work on time.

Accepting the premises, I can see that driving is not going to work. But there is still the option of the train. The fact that Marion hates taking the train doesn't mean she CAN'T take the train.

The author is assuming that "if you hate something, you CAN'T do it".

(D) is a TERRIBLY worded answer.

The claim that "Marion hates taking the train" is evidence that Marion will adopt a particular course of action [not take the train, and drive, first stopping by the bank].

The conclusion excludes the possibility of an alternative course of action [take the train, be at work on time].

Essentially this answer choice is saying that "if you hate something, you [probably] WON'T do it", but the author is treating it like "if you hate something, you [definitely] CAN'T do it".

== other answers ==

(A) was the confusion in this argument "many people" vs. "a particular person"? No, it was "hates doing" vs. "cannot do".

(B) this answer is an objection to an argument that says "Paul knows X. Therefore Paul knows the consequences of X." The conclusion of the argument about Marion has nothing to do with "knowing the consequences". It only has to do with whether something is possible.

(C) This accuses the argument of Whole to Part, in a sense. Because MOST want to avoid being late for work, Marion wants to avoid being late for work. That's nothing like the argument or the flaw.

(E) This answer would attack an argument that says "Paul sometimes does X. Therefore, Paul has good reason to do X."

==============

(D) attacks an argument that says "Marion will not take the train. Thus, Marion cannot take the train."

It's a frustrating correct answer since the argument never SAID Marion wouldn't take the train, it only implied it. The answer crucially, though, only says that there is EVIDENCE that Marion will not take the train. It doesn't say proof or that the author ever inferred that idea.

As Mary said earlier, this is a great example of Process of Elimination being our best (only) friend on questions such as these.

[keonheecho]

So for future reference, when an answer choice states "evidence that someone WILL do X", can that be interpreted as saying "evidence that SUPPORTS the conclusion that someone will do X?" This answer choice threw me off because the premise, "she hates taking the train" seems to be evidence for the conclusion that she MAY not take the train, and the "will" in the answer choice seemed extreme.