PT110.S3.Q6

PrepTest 110 - Section 3 - Question 6

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Support Standard archaeological techniques make it possible to determine the age of anything containing vegetable matter, but only if the object is free of minerals containing carbon. ███████████ ███████ ███████ ██ █████████ ████ ████████ ████████ ██ █████████ ███████ ███ ██ ██ ██████████ ██ ███████ ███████ ██ ████ ███████████ █████ ███████ ████████ ██████████ █ ███████ ██████████ ███████ ████ ███ ██████ ██████████ ██ ██ ███ ████████ ██ █████████ ███ ███ ██ ███████████ █████████ ██ █████████ █████ ████████ ██████████████ ███████████

Subtle Link Assumption · Object v. Sample

I think it’s reasonable at first to read the argument as being pretty airtight. As you read the stimulus, though, you should know the argument must be invalid somehow – else it wouldn’t be subject to weakening by the answer choices. With that prompting, identifying the link assumption gets a bit more achievable:

If there’s carbon in an object, standard techniques can’t tell us how old it is.
There’s carbon in the initial samples we collect from prehistoric paintings.
________
Standard techniques can’t tell us how old prehistoric paintings are.

There’s a difference between the initial samples we collect and the objects we’re eventually gonna test. We can’t achieve the initial sample-collection step without including some carbon, but perhaps there’s something we can do to address that further down the line.

Here’s an analogous argument:

To make a wedding ring, you need pure gold.
When gold comes out of the ground, it’s mixed in with dirt and other minerals.
________
We’ll never make a wedding ring.
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6.

Which one of the following, ██ █████ ████ █████████ ███████ ███ █████████

a

There exist several █████████ ██████████ ███ ██████████ ███████ ██ ███████████ ████████ ██ ██████████

(A) suggests there could be some other carbon-free technique we could use to collect these samples, but the premises directly establish that none of these techniques let us dodge the carbon. So no matter how many techniques we bring up, all of them are guaranteed to preserve the core problem from the stimulus.

7%
b

Laboratory procedures exist ████ ███ ██████ ███ ███ █████████ ████ █ ██████ ██ ███████████ █████ ██ ██████████

This exploits the link assumption between carbon being present in the samples we initially collect and carbon being present in the objects we eventually plan to test. Sample collection is one step in the process – perhaps step 2 is to remove the limestone, making the object amenable to these age-determining tests.

*A note on "standard archeological techniques": standard archeological techniques let you take an object and date it (if there aren't carbon minerals in it). The lab procedures mentioned in (B) come earlier in the process -- they make the object amenable to those techniques. So the story goes 1) collect the sample 2) use lab procedures to clean the sample, 3) use standard archeological techniques to date the sample.

85%
c

The age of ███ █████████ ██████ ███ ██ ██████████ ████ ███████ ████ ███████ ██ ███████████████ ██████

I get the appeal of (C), because “can’t we just control for the age of the limestone?” Like maybe we test the limestone alone and it’s 500 million years old, then just control for that as we test the limestone-polluted sample.

The problem comes with the premise, which directly tells us it’s impossible to date objects that have carbon minerals in them. So (C) feels like a good idea, but the premises directly tell us “that won’t work.”

6%
d

Prehistoric artists did ███ ███ ████████ █████ ████ █████████ ██████ ██ ████ █████ ███████

This argument is about what standard archaeological techniques can do, and standard archaeological techniques focus on vegetable matter. Prehistoric artists probably did use other materials in their art as well, but those materials aren’t subject to age-analysis using standard techniques.

1%
e

The proportion of ██████ ██ █████ ████████ ██ █████████ ██ ███ ████ ██ ███ ███████ ██ ██████████

(E)’s relevance loosely reflects (C)’s, where potentially the idea is that we could control or account for the limestone’s carbon somehow. The problem comes with the premise, which directly tells us it’s impossible to date objects that have carbon minerals in them. So (E) feels like a good idea, but the premises directly tell us “that won’t work.”

1%

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