Owner of JavaJoint: Over the past year, the coffee store has become a daily hang-out for more and more teenagers. Many of our adult customers do not appear comfortable with this kind of crowd and some of them have told me that they will no longer stop here for a coffee drink. Since my goal is to maximize our revenue, I want you to discourage teenagers from coming here and start cultivating a more adult crowd.

Store manager: Are you sure? On average, each teenager spends just as much as the average adult does, and we have far more new customers than we have lost over the past year.

The store manager responds to the owner by _____

a) questioning the veracity of owner’s evidence
b) arguing that it would be difficult to implement the owner’s directive
c) offering new evidence implying that the status quo is not incompatible with the owner’s goal
d) demonstrating that the average teenage customer is as profitable as the average adult customer
e) offering new evidence refuting that presented by the owner

The answer is C. Looking through the explanation, should it be that the status quo IS compatible with the owner's goal, not IS NOT? That's where I got confused. This is from one of the practice tests I took. Thanks!

You're right, but you weren't reading carefully enough:

"not incompatible" = compatible

The reason it is phrased in the double-negative is because the owner was suggesting that the status quo was incompatible with his goal, while the manager was suggesting that such was NOT the case.

Why is option D wrong? The manager states that the average teenager spends as much as the average adult, and also far more new customers than we have lost over the past year. Taking both these into consideration, wont it be right to say that average teenage customer is as profitable as an average adult...

The explanation in the answer choice only considers the first part of what the manager says. I am confused. Can someone please explain.

girl_jobless.

each teen spending just as much as the avg adult doesn't necessarily indicate profitability. If the avg adult spend $5, then for three teens that $15 in revenue. but what if there are ten adults who each spend $5, that's $50 in revenue. Instantly you can see that teens aren't as profitable as adults in this scenario.
Also, the argument doesn't say "the average teenager spends as much as the average adult". It says, on average each teen spends just as much as the average adult. That's a hell of a trick that the question writer pulls huh?

Additionally, the argumentl doesn't take into account that ALL the new customers are teens (that's an assumption). Some of the new customers could be adults, and if that's the case, the store may be losing those customers due to their level of feeling "uncomfortable".

Thank you so much dietric.williams. The answer choices are so close... I need to work more on watching out for tricks like that..

you're criticizing the right choice, but not necessarily for the right reason.

the objection you've raised here - that there could be more adults than teens - is irrelevant, since answer choice (d) is concerned with profit per person (read it carefully). since the choice is normalized in this way, it actually doesn't matter how many of each type of customer there are.

what matters here is that choice (d) confuses REVENUE with PROFIT. that is the problem.
i.e., we know only that each teenager SPENDS the same amount of money, on average, as does each adult (= equal revenues). however, we don't know the relative COSTS of the items that each is buying, so we can't tell who is more profitable.

in general, you should watch out for the two following CR errors:
* confusing profit with revenue, or vice versa
* confusing percentages with numbers

answer choices that do either of these things, in a CR problem, are almost always incorrect.