The only way that bookstores can profitably sell books at below-market prices is to get the books at a discount from ...

Mehran September 22, 2018

@melissajo please make sure you are reviewing previous threads before starting a new one.

Your question has already been asked and answered. Reposting the response here for your reference as well.

Alright, so let's diagram:

"The only way that bookstores can profitably sell books at below-market prices is to get the books at a discount from publishers."

So: if a bookstore can profitably sell books at below-market prices, then the bookstores got the books at a discount from the publishers.

P1: BPSBMP ==> GDP
not GDP ==> not BPSBMP

"Unless bookstores generate a high sales volume, however, they cannot get discounts from publishers."

So: if they can get discounts from publishers, then bookstores generate a high sales volume.

P2: GDP ==> GSV
not GSV ==> not GDP

"To generate such volume, bookstores must either cater to mass tastes or have exclusive access to a large specialized market,"

So: if we generate such volume, then the bookstore either caters to mass tastes or has exclusive access to a large specialized market.

P3: GSV ==> CMT or EALSM
not CMT and not EALSM ==> not GSV

We are asked what must be true, i.e. what can be properly inferred.

We can use the premises in the argument to properly infer answer choice (C): "A bookstore that profitably sells books at below-market prices gets discounts from publishers."

So: if a bookstore profitably sells books at below-market prices, then they get discounts from publishers.

(C): BPSBMP ==> GSV
not GSV ==> not BPSBMP

We can conclude answer choice (C) by connecting "P1" to "P2," like so: BPSBMP ==> GDP ==> GSV, to conclude: BPSBMP ==> GSV.

(A) is reversing P1 and remember, we don't just reverse! So (A) is incorrect. This highlights the difference between "only" and "the only".

Hope that helps! Please let us know if you have any other questions.

mikeheath May 11, 2020

I diagrammed "to generate such volume, bookstores must either cater to mass tastes or have exclusive access to a large specialized market" as an Either/Or statement. Is there a trick to know when either is mentioned in a statement it is either/or or apart of another sufficient-necessary statement?