Q8 - Department store manager: There

[christine.defenbaugh]

Lots of really great discussion here everyone! Let's break this question down from the top.

As this is a Necessary Assumption question, we need to start with a clear and concise breakdown of the core. farhadshekib has simplified it fairly well:

Premises:
If most customers take free gift wrapping --> expensive and time consuming
If few customers want free gift wrapping --> no advantage
Conclusion: No reason to offer free gift wrapping

Notice that the conclusion is a fact, and the premises are conditionals. What if those conditionals never get triggered at all? What if 40% of the customers wanted free gift wrapping? (40% is more than 'few', but less than 'most'.) We don't know anything about what happens in that scenario! If that happened, there might be a reason to offer free gift wrapping!

(E) nails this. The argument assumes one or the other of the two conditionals will get triggered. If neither occurred, and we were in some totally different scenario that we know nothing about, then the conclusion wouldn't make any sense.

Notice that there's another assumption here, that could just as easily been tested: the argument is also assuming that if something is time-consuming and expensive, that means there can't possibly be any reason to offer it. If there might be a reason to offer it, even despite that cost and time, then the final conclusion is crazy.


Not Assumed
(A) False comparison. The only reference to cost is the premise 'if most customers take the offer, it will be expensive'. There's no comparison we need to draw between this holiday season and last.

(B) Irrelevant conditional. The argument makes no reference to slowing shoppers down.

(C) False opposite. The argument is about free gift wrapping. As related as it might feel, charging for gift wrapping is actually out of scope. Negate this answer to double-check.
NEGATION: It would NOT be to the store's advantage to charge for gift wrapping.
The fact that its not an advantage to charge doesn't destroy the conclusion that there's no reason to offer it free. Maybe there's just no advantage to doing either one!

(D) The cost of informing customers is out of scope. Even if it were free to inform them, that doesn't damage the conclusion.


Remember, the first stop should always be a clear and concise breakdown of the core, and the disconnect therein!

Please let me know if you have any additional questions!


#officialexplanation

[cimani.w]

Why can't the aswer choice be c?

[ManhattanPrepLSAT2]

We're asked to identify a necessary assumption -- something that MUST be true in order for the argument to be true.

Must (C) be true in order for the argument to be true? No. The argument is about the reasons for not giving away free gift-wrapping. Answer (C) is about something else -- the consequences of having charged gift-wrapping.

To illustrate this issue, here's a simple analogy:

Imagine there was a rule that said "No one under the age of 13 will be admitted to law school."

In order for this rule to be sound, MUST IT BE TRUE that everyone over 13 will be admitted? No.

The manager is saying there is no reason to offer free gift wrapping.

For him to his case, must it be true that offering charged gift-wrapping would be of benefit? No.

Hope that helps! Please feel free to follow up if it doesn't.

[farhadshekib]

Let's look at it another way:

Conclusion: there is no reason to offer our customers free gift wrapping this holiday season.

Why?

1) If most customers take this offer, it will be expensive + time consuming.

2) if only a few customers take this offer, there is no advantage in offering it.

Now, upon reading this, I asked myself: do the premises, that is: 1 and 2, adequately support the conclusion that there is "no reason" to offer free gift wrapping?

No, not really.

The biggest gap here is that the argument assumes, without justification, that the number of customers who take this offer will not be more than a few, but less than most.

In other words, the argument assumes (E): either few customers or most customers will want this offer.

With respect to (C), try negating it: it would not be to the store's advantage to charge customers for gift wrapping services.

Does it weaken the conclusion? Not necessarily... The conclusion does not say that the store should charge customers for gift wrapping.

Rather, the conclusion simply warns against offering free gift wrapping services.

Indeed, the conclusion leaves open the possibility that gift wrapping is not offered at all.

So, (C), when negated, wouldn't hurt the argument; therefore, it cannot be correct.

[jelgamal]

I initially choose the right answer but it looked like a premise booster. I've had this problem with sevral other questions....how can differentiate..?

[Chadmds]

I want to see if I have identified the correct assumption(s) for this question.

1.) The stimulus assumes that there will be either a few customers who want it or if most customers take the offer, and that a middle ground, many customers wanting it, is not possible.

2.) The stimulus concludes that there is no reason to offer customers the wrapping service because it will either be expensive and time consuming or won't be advantageous. Couldn't there be other reasons that may make the services slightly beneficial?

[Yit HanS103]

I was between A and E.

Even though A only addresses a part of the premise, and if you negate A, it destroys the premise, which is why I also wasn’t sure about A. It sounded better than E.
E to me sounded like a premise booster and also when negate it, it doesn’t destroy the argument, it only contradicts the premise.

1. We accept all premises as facts, so A and E negating both only contradicts the premises. It doesn’t destroy the argument .
2. In necesarry assumption, when you negate a choice does it have to destroy the conclusion or the whole argument ?

Thank you !!!

[ohthatpatrick]

Negating (A) says that "gift wrapping would cost the store the same as in previous seasons or less than in previous seasons".

Nothing in the paragraph says anything about how much gift wrapping cost in previous seasons. I don't know how you're thinking negating (A) contradicts anything, when we never heard about how much gift wrapping cost in previous seasons.

Meanwhile (E) is not stating something we already know.

You have to differentiate between conditional statements ("IF"), which are hypothetical, and actual statements of fact.

Consider this argument.

If it rains on Saturday, the picnic will be canceled. Thus, the picnic will probably be canceled.

What are we assuming?
(A) It will probably rain on Saturday

That's not a premise booster. We never heard anything about what the probability of rain on Saturday was. And the author NEEDS there to be probable rain if he's thinking that the trigger of this conditional rule will probably be triggered.

Similarly, in this argument the author is thinking that one his two conditional rules will be triggered.

Say that 40% of customers wanted gift wrapping.
Did the author account for that scenario?

No ... because 40% is not "most customers", so we haven't triggered THAT rule.
And 40% is more than "only a few customers", so we haven't triggered THAT rule.

Maybe 40% is a sweet spot where we actually benefit from offering free gift wrapping.
Since the author didn't account for possibilities in between "only a few" and "most", she hasn't convinced us that gift wrapping will definitely not be worth it.

In order to convince us of that, she needs to assume that one of her two rules will be triggered. That's what (E) is doing.

In regards to your broader question about the Negation Test, the correct answer when negated does not need to falsify the conclusion. It just needs to weaken the argument.

Just think of your task on Necessary Assumption as either
"Which answer best matches the author's logic (without going too far)?"
or
"Which answer, when negated, most weakens?"

Either mindset will always lead you to the correct answer, but you'll probably find some correct answers that are easier to see in terms of "Yes, the author was clearly thinking this" and other correct answers that are easier to see in terms of, "Yes, were I to negate this, it would definitely weaken the argument"