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

Naz March 11, 2015

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.

Hope that clears things up! Please let us know if you have any other questions.

brittneymfrey@gmail.com May 5, 2018

I think the above is a typo. we do not need to connect anything as answer choice C is the correct answer from the first premise.

What the above says is connecting an argument that generates high sales volume, which is not what C says. This looks like it meant to say B possibly? It looks like both B and C are correct, please advise.

brittneymfrey@gmail.com May 5, 2018

I think the error is in the unless statement. Because it says cannot, I thought it would be NOT DP > GHSV in order to negate it.

YHD August 1, 2018

I thought that what follows after 'Unless' and 'only' is Necessary condition?


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

Then shouldn't this sentence then diagrammed as
GDP --> BPSBMP

Please explain

MichelleRod August 4, 2018

Thanks for your question @YHD

You are correct that "unless" and "only" precede necessary conditions. Remember from the same lesson, however, that "THE only" precedes a sufficient conditions