#9 - Advertisement: Clark brand-name parts are made for cars

[sjlsat]

The negation of answer E would be "parts made for cars manufactured in our country could be poorly constructed." That actually strengthens the argument, Julie, because the author thinks some foreign-made parts may be poorly constructed. The negation of answer E does nothing to weaken the claims that Clark parts are the only ones to pass those tough tests, and that they are therefore more reliable than others.

But the negation of D is "parts that satisfy those tests ARE as poorly constructed as foreign parts", and if that's the case then there is no reason to prefer Clark parts. The argument completely falls apart.

Hi,

I'm still having trouble understanding why E is wrong. The first line of the stimulus says Clark brand-name parts are made for cars manufactured in this country. So wouldn't the negation of E, which is "if parts are made for cars manufactured our country, they are poorly constructed," include Clark brand-name parts as well? If someone could explain why my reasoning is incorrect/what I'm missing, that would be great. My contenders were D and E for this one.

Thank you!

[Jonathan Evans]

Hi, sjlsat!

Focus on the Assumption-Negation Test™ that Adam performs on answer choice (E).

The negation of a conditional is to consider the sufficient statement true with a false necessary condition.

As Adam writes, the negation of (E) is "parts made for cars manufactured in our country could be poorly constructed."

Although parts made in our country could be poorly constructed, these need not include the Clark parts. Thus it still could be possible that people should insist on the Clark brand name parts.

I hope this helps!