Mayor of Plainsville: In order to help the economy of Plainsville, I am using some of our tax revenues to help bring ...

Naz July 21, 2014

You've correctly identified this question as a Strengthen with Necessary question. So our correct answer will both strengthen the argument and, if it is negated, it will make the argument fall apart.

The conclusion of the argument is: "You (the mayor of Plainsville) must have interests other than our economy in mind."

Why? Because we know that the mayor has proposed to use some of the tax revenues of Plainsville "to help bring a major highway through the town and thereby attract new business," in order to "help the economy." However, the Citzens' group explains that if the mayor were truly interested in helping Plainsville's economy, then she would "instead allocate the revenues to building a new business park," because it would bring in double the business than the mayor's proposed highway.

Now let's look at answer choice (B): "The mayor accepts that a new business park would bring in more new business than would the new highway."

This strengthens the argument because if the mayor does agree (i.e. "accept") that a new business park would bring in more business than a new highway, then she couldn't have solely proposed the new highway to help the economy. If her only interest was the economy, then she would have obviously chosen the option that brought about more business, i.e. the new business park.

Thus, exactly as you have pointed out, if we take answer choice (B) to be true, then the argument of the citizens' group is strengthened because the mayor is choosing an option that she does not accept to be the most profitable, i.e. she must have interests other than Plainsville's economy.

Next, we must see if the argument would fall apart if we negate answer choice (B).

Negation: "The mayor does not accept that a new business park would bring in more new business than would the new highway."

This will make the conclusion (i.e. that the mayor must have interests other than Plainsville's economy in mind) fall apart because if the mayor does not accept that a business park would bring in more new business than the new highway, then her proposal for the new major highway could have been made "in order to help the economy of Plainsville."

Hope that was helpful! Please let us know if you have any other questions!

Derek July 22, 2014

Ok, I get it. I read it wrong. Thank you for the help

patentastic November 2, 2014

Ah! Thanks a lot!

Jessica-Killeen February 6, 2019

why is the answer to this question not E?

Ravi February 7, 2019

@Jessica-Killeen,

Happy to help.

As Naz noted above, this is a strengthen with a necessary premise question.

The question stems asks, "The argument by the citizens' group relies
on which one of the following assumptions?"

We know we're focused on choosing the answer choice that's a necessary
premise, which means the answer choice must be true in order for the
citizens' group's argument to stand a chance.

We can use the negation test to see whether or not a given answer
choice is a necessary premise. In negating the answer choice, we're
basically taking out that necessary premise and pretending that the
opposite is actually true. If, when the negation is true, the argument
falls apart, we then know that the original form of the answer choice
is a premise that must be true in order for the argument to stand a
chance, so it's a necessary premise. Without the necessary premise,
the argument loses.

You asked why (E) isn't right. Let's take a look.

(E) says, "Plainsville’s economy will not be helped unless a new
business park of the sort envisioned by the citizens’ group is built."

The negation is (E) is, Even if the business park of the sort
envisioned by the citizens' group is not built, Plainsville's economy
can still be helped.

(E)'s negation is actually compatible with the citizens' group's
argument because the citizens' group is not assuming that the business
park they mention is the sole way to help the town's economy; rather,
they simply assume that it's the best way to help the economy. Their
assumption doesn't prevent there from being other things that could
help the economy of the town even if the business park isn't built.
(E)'s negation doesn't wreck the citizens' group's argument, so it is
not a necessary premise. As a result, we can get rid of this answer
choice.

Does this help? Let us know if you have any more questions!

Samantha-Alexis June 2, 2019

Hey Ravi,

For you explanation for answer E, I am confused on why you switched the S and N terms when negating, is it because the original statement involves unless?

Ravi June 3, 2019

@Samantha-Alexis,

Great question. Regarding (E)'s negation, I didn't actually switch the
S and N terms when negating.

The original statement is

Helped - >Built

The negation is

Helped and not built

The negation says "can still be helped," and this indicates that this
isn't a traditional S and N relationship. The negation of the original
statement means that the sufficient condition could occur and the
necessary condition might not occur, but it doesn't mean that the
necessary condition must not occur.

Hope this helps. Let us know if you have any other questions!

Shirnel May 29, 2020

How would I know to negate in this non-traditional way that Ravi used above? This now confuses me.

Malen September 1, 2020

agreed this needs clarification. This is not the first time I've seen a deviation from the S&N negation tactics. I interpreted this as, Help economy --> Built (the negation would be: not built --> not help economy)

AneeshU June 16, 2022

Why does the Mayor need to accept that the business park would bring in more business? For all we know, the Mayor refuses to accept that the business park would bring in more business because of her interest in building a highway.

I chose C on the basis that if the highway had other economic benefits, other than bringing in business, the citizen's argument would fall apart.

Emil-Kunkin June 28, 2022

Hi AneeshU,

You are right that the mayor does not have to accept that the park would bring in more new business than the highway. It is entirely possible that the mayor has a different economic analysis, in which the park is worse than the highway.

However, the group's argument that the mayor must not be acting in the interests of the economy does rely on the premise that the mayor agrees the park is better than the highway. If the mayor thought that the highway was better than the park, then the mayor would indeed be acting in (what he thinks is) the interest of the economy. This would undermine the conclusion that the mayor is acting in the interest of something other than the economy.