Of all the houses in the city's historic district, the house that once belonged to the Tyler family is the most famou...

Naz September 16, 2014

Which was the answer choice you went with initially?

The flaw in this question is not a Quantifier flaw--it is a Part to Whole flaw.

We are told that the house that once belonged to the Tyler family is the most famous of the houses in the city's historic district, i.e. in one part of the city. From this, it argument concludes that the Tyler house must be the city's most famous house, i.e. one characteristic of a part of a whole must be shared by the whole. Well, just because it is the district's most famous house does not mean it is the city's most famous house.

So the flaw is that the stimulus is taking a characteristic of a part of a whole (that one house is the most famous in a specific district of a city) to mean that the whole has that same characteristic (that house is the most famous in the entire city).

Thus, the correct answer must have this same flaw, which answer choice (E) does. The most beautiful flowers in the university's botanical garden (one part of the region) are the most beautiful. Therefore, the Oakland roses must be the most beautiful flowers in the entire region. Answer choice (E) has the exact same flaw.

If our flaw was based in Quantifiers, then our correct answer would also have to have quantifiers. For instance:

P1: A-most-B
B-some-A

P2: C ==> B
not B ==> not C

C: A-most-C
C-some-A

The correct flawed parallel answer choice must also have quantifier words. But, it does not necessarily have to have the same quantifier words; it merely needs to have the same flaw.

For example, our correct answer could be:

P1: C-some-D
D-some-C

P2: E ==> D
not D ==> not E

C: C-some-E
E-some-C

The above example has the same flaw as the first quantifier example even though the first one has a "most" and the second one doesn't. You want to focus on the flaw as opposed to the exact syntax.

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

alige December 25, 2018

Can you explain why A is incorrect?

Ravi December 26, 2018

@alige,

Happy to help. Answer A is very tricky, as it has a very similar wording structure to what we see in the stimulus.

However, unlike the stimulus and the correct answer (answer E), answer A is a valid argument and does not possess flawed reasoning. Let's take a look.

Answer A says, "of all the peaks in the central mountain range, Mount Williams is the tallest. Since the tallest peaks in the entire region are in the coastal mountain range, Mount Williams must be the region's tallest peak."

We know that Mount Williams is the tallest peak in the coastal mountain range. We also know that the tallest peaks in the entire region are in the coastal mountain range. If Mount Williams is the tallest peak in the portion of the region with the tallest peaks, then it must be the region's tallest peak. This is a valid argument, unlike the flawed part-to-whole reasoning we saw in both the stimulus and in answer E.

Does this make sense? Let us know if you have any other questions!