PT8.S1.Q10 - if the public library shared

time_to_go

I think the error that author makes is false equation (population # = # of library users) but can someone explain answers (B) and (E) in further detail? Thanks in advance!

runiggyrun

You are on the right path - that would be a good flaw to think about before reading the answers, but the answers go for a more subtle error than population=number of library users. They go for population WITHIN walking distance=population in the center of the town.
That makes B correct - if central Glenwood is a lot more spread out than the central Redville, spreading beyond "walking distance" from where the library is located, then even though there are more people in that central area, not all of them are necessarily going to be within walking distance from the library.
Answer E. falls under out of scope. The conclusion of the argument is that more people will be within walking distance of the library. The fact that some people walk 20 miles to the current location is not relevant to the argument.
Hope this helps.

nye8870

@runiggyrun
"The area covered by central Glenwood is
approximately the same size as that covered
by central Redville." What does -covered- mean. Walking distance or just the square footage attributed to what the town calls -central- ?

runiggyrun

@nye8870 - I read "the area covered" as square footage. Basically the assumption made is that the population density is similar, so the town with more people living in the center will have more people near the library. I'm thinking of an extreme case of Manhattan vs LA. Central LA (a very vague term, I know) might have more people than Manhattan, but any place in Manhattan will be within walking distance to quite a few people while nowhere in what's considered "central LA" will, because it's just so spread out that very few people are within walking distance of anywhere.

nye8870

@runiggyrun That is what I figured too but I am not confident in the "density" assumption. I agree that could be the case however I can also drum up scenarios where people live within "central" regardless of total acreage and still cant walk to their library. e.g. most people tend to live in the highrise condos just outside of the considered "walking distance" and still withing central limits.

Lizardking-1

For people searching the forum for this question, I thought I'd add to the explanation of why E is wrong. I found it fairly easy to see why B is strengthens, but had difficulty totally eliminating E. Powerscore // manhattan explanations for the elimination of E were pretty hand wavy.

We want to strengthen contention that if library is relocated, it will be within waking distance to more users.

The mistake E makes is to focus on the the people who are walking vs. the # of people within walking distance. We don't care about how far people are walking to the library in Redville. Sure, maybe everyone that walks to the library isn't within walking distance. This doesn't actually help the argument. According to E, It could be that there are far more people / library users within walking distance to the library at it's current location in Redville than there would be if it were moved. Maybe the users that are currently within walking distance choose to drive, or moped, or ride their mules to the library. # of people Actually walking vs. # of people within walking distance= two different things. So this doesn't do anything for the argument. It misses the point.