#21 - Bank deposits are credited on the date of the

[Administrator]

Complete Question Explanation

Parallel Flaw—SN. The correct answer choice is (C)

This tricky problem is a good example of why you can never simply glance at a question stem and
assume that you know what it says. The stem in this problem specifically indicates that the correct
answer must parallel both the logical flaws in the stimulus. As you might expect, before you reach
the correct answer the makers of the test have placed answers that display only one of the flaws.

The most obvious error in the stimulus is a Mistaken Reversal (remember, “only when” introduces a
necessary condition):

     CD = bank deposits credited on the day of the transaction
     3 = deposit made before 3 P.M. on that day
     A = Alicia knows

     First premise: CD 3

     Second premise and conclusion: 3A CDA

Although most students recognize the Mistaken Reversal, they make the error of quickly glancing
at the question stem, and when they see the word “exhibits” they move to the answers without
realizing there is a second flaw. Although this action is not problematic because the correct answer
will contain a Mistaken Reversal, the danger is that a student will select the first Mistaken Reversal
that appears without examining the second flaw, and indeed, about half of the test takers erroneously
choose answer choice (A) or (B), with answer choice (B) being the more popular of the two. A
student considering each answer would recognize that answer choices (A), (B), and (C) each contain
a Mistaken Reversal, and thus there must be an additional differentiating factor in play.

We will dispense with answer choices (D) and (E) because they both contain the Repeat conditional
form. In order to decide between answer choices (A), (B), and (C), we must re-examine the stimulus
and discover the second error, or at least discover a factor that will allow us to choose one of the
remaining three answers. The second error is tricky, and centers around the idea of what Alicia
“knows.” Look carefully at the wording in the stimulus: Alicia “knows” that the deposit was made
before 3 P.M., but does the stimulus indicate that she knows about the bank policy where bank
deposits are credited on the date of the transaction only when they are made before 3 P.M? There is
no indication that she knows this rule is in effect, and so there is no way Alicia could then “know”
with certainty that the bank deposit was credited on the date of the transaction (this is the case
irrespective of the Mistaken Reversal error that is also present). The issue of “knowing” one thing
but not necessarily the other is the second error, and a quick examination of the three remaining
answers reveals that only answer choice (C) contains the same flaw of not “knowing.” Answer choice
(C) is therefore correct.

Although the “double error” language appears infrequently in Parallel Reasoning questions, you
can use the knowledge that such questions exist to implement a valuable safeguard strategy: if you
find an attractive answer choice early on and you are contemplating skipping the remaining answer
choices, before you exit the problem check to make sure the question stem does not contain a twist
like the one in this problem. Doing so could save you from missing a question.

[smile22]

I diagrammed this stimulus as follows:

P1: Bank deposits credited on date of transaction transaction made before 3pm
P2: Alicia knows deposit was made before 3pm
C: Alicia knows deposit will be credited on date of transaction.

I was able to conclude that one of the flaws is a mistaken reversal. However, the question stem says that there are two flaws. What is the second flaw?

Thank you for your help.

[Emily Haney-Caron]

Hello,

Good question. This one is a little bit tricky to spot with the added mistaken reversal. The second flaw is assuming that necessary equals sufficient. For the bank deposit to be credited on the date of transaction, it is necessary for the transaction to be made before 3 pm, but we don't know whether that guarantees that it will be credited that day.

Does that help?

[ehilliard]

Hello,

I had this similar question. Can you explain the second flaw a little more? I don't understand how mistaking a necessary condition for a sufficient condition is different from the act of making a mistaken reversal.

Can you also clarify what specifically distinguished answer choice B from C?

Thanks!

[Emily Haney-Caron]

Thanks for the question! I'm glad you asked for clarification. The mistaken reversal/sufficient-necessary flaw is one of the flaws in this question. The second flaw here is an assumption that Alicia KNOWS the information contained in the first sentence; if she doesn't, then there is no way for her to know the information in the third sentence. B and C both contain the sufficient-necessary mistake, but only C assumes with no basis that someone knows critical information (here, assumes George knows "George will be promoted to shift supervisor only if Helen resigns"). Does that help?

[ehilliard]

Oh, I see. I merely took the statement about knowing the deposit was made as a factual statement. Since this is a first family question, isn't that something that should be taken to be true?

I do clearly see the difference between the answer choices now. Thank your for that clarification!

[Jon Denning]

That's a good question! You can take the information as factually true, but you should always question whether ideas/scenarios given are logically valid. That is, you can trust that an author believes his or her own conclusion, but you have to consider whether that belief is reasonable/well-founded. Make sense?

[ehilliard]

Ah, okay that makes sense! Thanks!

[ncolicci11]

Powerscore,

I just am looking for a little more clarification on the second flaw. I was easily able to identify the mistaken reversal but whiffed on the second flaw. So, for future questions where I may encounter this second flaw, should I always be suspicious of a claim that someone in the stimulus knows something?

Thanks!

[Adam Tyson]

You should always be suspicious of everything on this test, ncolicci11! But be especially suspicious of shifts terminology. Something being true doesn't prove that someone knows that to be the case. Someone having a motive doesn't prove that they acted on that motive. Just because my stationary is made from recycled paper doesn't mean it is recyclable. A claim that one thing is good does not prove that it is better than another thing. The authors of this test are constantly changing terms and concepts in their conclusions, and that is the source of many of the flaws on the test. That's why we have to always be on our toes looking for those slight (and not so slight) differences in words and meanings. In short, read carefully, and be a skeptic!