#13- Mayor: To keep our neighborhoods clean, every street in

[Administrator]

Complete Question Explanation

Must Be True - SN The correct answer choice is (D).

The stimulus of this fact set is filled with conditional reasoning indicators, including "every," "if," and "all." This should alert the test-taker to grab their pencil or pen and start diagramming, for the question will likely be based on that reasoning and easily answered once all the pieces are put in place.

The first sentence gives us this relationship:

SIT (Street In Town) Sw1+M (Swept at least Once a Month)

The second sentence can be diagrammed as:

NMFS (Need More Frequent Sweepings) QIS (Qualified for Interim Sweepings)

Finally, we get a multi-conditional claim:

QIS
+                            SwI (Swept Immediately)
RIS (Request Interim Sweeping)

From this we can build a chain - if a street needs to be swept more frequently, and asks to be swept in the interim (meaning between the monthly sweepings), they will be swept immediately. That means that they will not have to wait the whole month for their usual sweeping, but will get one sooner. That is a pretty good prephrase, but we should also be on the lookout for a contrapositive, such as "if a street is not swept immediately then either it did not request an interim sweeping or it did not qualify for one."

Answer choice (A): "Construction Under Way" is NOT a sufficient condition for qualifying for interim sweeping. The street has to NEED more frequent sweeping, and construction is only mentioned as one possible source of the extra mess (and only major construction is actually mentioned, so maybe minor construction won't be enough).

Answer choice (B): Being qualified for an interim sweeping isn't sufficient - the neighborhood also has to request that sweeping to guarantee that it will happen immediately instead of waiting for the regular monthly sweeping.

Answer choice (C): This is a Mistaken Reversal of a portion of the final conditional claim. It could be true that some street gets swept more often even if it is NOT qualified and even if nobody requests it. Being qualified and requesting an interim sweeping is sufficient, but that doesn't mean it is necessary!

Answer choice (D): This is the correct answer choice. This follows from our conditional chain and must be true. If a street is qualified and requests an interim sweeping, they will get one immediately. The fact that they call it an "interim" sweeping very strongly suggests that it is not the usual monthly sweeping, but happens sooner than it otherwise would. Some might want to quibble and say "okay, but they could then delay the next sweeping so they still only get one per month," but the stimulus was about getting "more frequent" sweepings, not just an earlier one!

Answer choice (E): Essentially the same as answer C, this is a Mistaken Negation of the conditional rules in the stimulus. Qualified streets where neighbors submit a request will be swept immediately, but so might some other streets.

[kcho10]

How is ans choice D not a mistaken reversal?

Sweep 2+ times-->qualified for sweep
qualified + request-->immediate sweep

D says that a qualified neighborhood that requests an interim sweeping will have its streets swept more than once a month. But in order to infer that it will have its streets swept more than once a month, don't we have to go backwards on the conditional chain from qualified to sweep 2+times?

[Kristina Moen]

Hi kcho,

Take a look at this phrase: "All requests for interim sweepings from qualified neighborhoods will be satisfied immediately."

How will that be request be satisfied? By interim sweepings. What are interim sweepings? Why, these are sweepings more than 1x per month! You said that the neighborhood will get an immediate sweep, but the request is for interim sweepings (i.e. more than 1x/month).

I will break down the 2nd sentence:
"If a neighborhood needs more frequent sweepings, due to excessive dirt from major construction for example, that neighborhood will be qualified for interim sweepings." could b diagrammed as:
Need for more frequent sweepings (i.e. more than 1x/month) qualified for interim sweeping

You're right that we can't go backwards and say that any street that qualified for interim sweeping has a need for those extra sweepings. But what we do know is that if a qualified street requests interim sweeping, then they will GET those extra sweepings.

[mjb514]

I'm still not understanding why A is wrong. The passage clearly states, "If a neighborhood needs more frequent sweeping... that neighborhood will be qualified for interim sweeping." A seems like an exact restatement of whats in the passage. The only difference is that it states "All neighborhoods." Is the presence of "all" the reason why A is wrong?

[Claire Horan]

Hi MJB514,

Answer (A) is wrong for a more fundamental reason than the word "all." In fact, we know from the stimulus that all neighborhoods that need more frequent sweeping are qualified. The stimulus does not say all neighborhoods with construction need more frequent sweeping, and it does not say that all neighborhoods with construction are qualified. The reference to construction says "major construction," and regardless, it doesn't even say that all neighborhoods with "major construction" are qualified. There may be neighborhoods with construction that nonetheless do not "need more frequent sweeping."

I hope this helps!

[gwlsathelp]

Right off the bat, I noticed the SN reasoning; however, I diagrammed it wrong. I took "to keep our neighborhoods clean" to mean the sufficient indicator "in order to keep [...]." In this case, it's not used like that, but it can be.

As a whole, re-reading the stimulus, this appears to be easy. There is a general rule: all streets in neighborhood are to be swept at a minimum once per month. Answer choice D is applying the neighborhood's subcategory that "a qualified neighborhood that requests an interim sweeping" not only gets at least once a month sweeping, but it gets more because of its qualification and request.