Mayor Delmont's claim!

[gmat_for_life]

Political Advertisement:
Mayor Delmont's critics complain about the jobs that were lost in the city under
Delmont's leadership. Yet the fact is that not only were more jobs created than
were eliminated, but each year since Delmont took office the average pay for the
new jobs created has been higher than that year's average pay for jobs citywide. So
it stands to reason that throughout Delmont's tenure the average paycheck in this
city has been getting steadily bigger.
Which of the following, if true, most seriously weakens the argument in the
advertisement?
(A) The unemployment rate in the city is higher today than it was when
Mayor Delmont took office.
(B) The average pay for jobs in the city was at a ten-year low when Mayor
Delmont took office.
(C) Each year during Mayor Delmont's tenure, the average pay for jobs that
were eliminated has been higher than the average pay for jobs citywide.
(D) Most of the jobs eliminated during Mayor Delmont's tenure were in
declining industries.
(E) The average pay for jobs in the city is currently lower than it is for jobs
in the suburbs surrounding the city.

[MartyMurray]

The question asks which choice weakens the argument. So the first thing to do is find the conclusion of the argument and the premises upon which that conclusion is based.

The conclusion is "throughout Delmont's tenure the average paycheck in this
city has been getting steadily bigger."

The premises are "more jobs [were] created than were eliminated" and "each year since Delmont took office the average pay for the new jobs created has been higher than that year's average pay for jobs citywide."

(A) The fact that the unemployment rate has gone up seems to weaken the conclusion, but I guess the rate of employment does not really figure into the calculation of the average paycheck of those working. Possibly one could say that those unemployed get paid nothing, and so an increasing rate of unemployment lowers the average paycheck, but I am guessing that there is a better answer choice, one that does not require getting philosophical about the average paycheck of people who don't have jobs.

(B) This is irrelevant. To answer the question we need something that indicates that average pay did not go up while he was in office.

(C) This seems to be the best answer. If the pay for eliminated jobs was higher than the average pay for jobs citywide, even though the pay associated with newly created jobs was higher than the citywide average for the year in which they were created, the pay associated with the new jobs may not be as high as the pay for lost jobs had been. So the average paycheck may have decreased even though the pay associated with the new jobs was higher than the average pay for jobs citywide.

(D) What industries the eliminated jobs had been in does not affect the average pay.

(E) The difference between pay for jobs in the city and pay for jobs in the suburbs has no bearing on a conclusion about the change over time in average pay for jobs in the city.

So the only one that undermines the conclusion is C.

[VivianKerr]

This is one of those question that really proves the point that if you don't carefully analyze and break down the argument, you'll probably get the question incorrect.

Ask yourself: what are we meant to notice?

Here, we are given facts about new jobs $, eliminated jobs $, and overall jobs $ in the evidence. Then, notice how the conclusion ONLY focuses on overall jobs $ based on new jobs $.

It introduces a concept shift with the important keyword "throughout," and neglects to include the third piece of evidence: "eliminated job $." The correct answer must correctly tie BOTH of these ideas together.

Here's how I'd analyze this problem on my scratch paper:



We may not know exactly how the correct answer will be phrased, but we understand the "job" it will do.

Prediction: WEAKEN by showing the eliminated job $ matters throughout!

Now, we don't even need to waste too much time analyzing the choices. It's clear that so many of these choices don't even remotely deal with the topics at hand: (A), (D), and (E).

You only need to quickly re-read (B) and (C) to grasp that (C) is a much better match for our prediction.

Takeaway: Always, ALWAYS write down a prediction and think for yourself before reading the CR answer choices!

[VivianKerr]

Sorry, just realized there's a typo in my notes. The prediction should read "does" and not "doesn't." #tutorfail

[Brent@GMATPrepNow]

If you're interested, we have a free video on answering Weaken the Argument questions - https://www.gmatprepnow.com/module/gmat ... video/1136

There are some practice questions following that video for extra reinforcement.

Cheers,
Brent

[gocoder]

Choice C: Each year during Mayor Delmont's tenure, the average pay for jobs that
were eliminated has been higher than the average pay for jobs citywide.

I was bit uneasy with this choice. Here is my chain of thought.

premise:
avg pay of new jobs>avg pay of the city jobs.
num. of new jobs >num. of lost jobs.

OC:
avg pay of lost jobs>avg pay of the city jobs.

case 1:
avg pay of new jobs>avg pay of lost jobs>avg pay of the city jobs

Then, overall average pay and total pay of the city could have increased, thus strengthening the conclusion.

case 2:
avg pay of lost jobs>>avg pay of new jobs>avg pay of the city jobs
In this case, the total deficit because of lost jobs is greater than that of newly added jobs, thus weakening the conlusion

As per choice C, both cases above are possible. Let me know if any flaw in this reasoning.

[DavidG@VeritasPrep]

Choice C: Each year during Mayor Delmont's tenure, the average pay for jobs that
were eliminated has been higher than the average pay for jobs citywide.

I was bit uneasy with this choice. Here is my chain of thought.

premise:
avg pay of new jobs>avg pay of the city jobs.
num. of new jobs >num. of lost jobs.

OC:
avg pay of lost jobs>avg pay of the city jobs.

case 1:
avg pay of new jobs>avg pay of lost jobs>avg pay of the city jobs

Then, overall average pay and total pay of the city could have increased, thus strengthening the conclusion.

case 2:
avg pay of lost jobs>>avg pay of new jobs>avg pay of the city jobs
In this case, the total deficit because of lost jobs is greater than that of newly added jobs, thus weakening the conlusion

As per choice C, both cases above are possible. Let me know if any flaw in this reasoning.

You're right that we don't know how the average salary of the new jobs compares to the average salary of the eliminated jobs.

Think of it this way: If we introduce new jobs whose salary is higher than the overall average, and no jobs were eliminated, the overall average has to go up, right? But if we introduce new jobs with a higher than average salary and also eliminate jobs with a higher than average salary, we no longer know what happened to the overall average. In other words, C introduces doubt, and this is enough to weaken the conclusion.