Twist Weaken Ques

[ranjeet1975]

In the United States, of the people who moved from one state to another when they retired, the percentage who retired to Florida has decreased by three percentage points over the past ten years. Since many local businesses in Florida cater to retirees, this decline is likely to have a noticeably negative economic effect on these businesses.
Which of the following, if true, most seriously weakens the argument?
A. Florida attracts more people who move from one state to another when they retire than does any other state.
B. The number of people who move out of Florida to accept employment in other states has increased over the past ten years.
C. There are far more local businesses in Florida that cater to tourists than there are local businesses that cater to retirees.
D. The total number of people who retired and moved to another state for their retirement has increased significantly over the past ten years.
E. The number of people who left Florida when they retired to live in another state was greater last year than it was ten years ago.

The OA is D but I think that C is right as other business that cater to tourists are more and then the economy will not suffer.

Please explain where am I wrong?

[ps63739]

Argument says that the percentage that moved to Florida (than other states) have decreased by 3%. Which in turn will affect the bisinesses over there.

Now any argument that tells us that - despite the percentage decrease the number of people to going to Florida is constant, or maybe higher the Argument's conclusion is weaken.

D - If the total number of retired people moving to All states have increased, then comparitive 3% decrease would not have a significant in Florida's business.
Say there were 100 people retiring earlier and percentage moving to Florida was 20%, to Texas 50% and to NJ was 30%. (Means 20, 50 and 30 respectively to these states).
Now say 1000 people now retiring to other states and percentage to Florida decreased by 3% to 17%. So now people who move to florida will be 170 (More than what it was). So it weakens the conclusion.

C - We cannot guess the number of tourists who are coming to Florida, infact there is no information on tourists in the Argument. So we cannot say if it would strengthen or Weaken the argument.

[Ben Ku]

Please cite the source (author) of this problem. We cannot reply unless a source is cited (and, if no source is cited, we will have to delete the post!). Thanks.

[i've seen evidence that this is a gmat prep problem, so let's allow it to stand.
-- ron]

[salman.bakhrani]

Ron, how would you rule out A?

[RonPurewal]

Ron, how would you rule out A?

well, ok, first you have to make sure you understand the argument -- the argument is looking at a decrease the proportion of interstate retirees who are moving to florida, and interpreting this as something that is going to hurt florida's businesses.
the only reasonable way to process this argument is to realize that the author is confusing a percentage/proportion decrease with an absolute decrease (i.e., decrease in the actual number of retirees moving into the state), since a decrease in that actual number is the only thing that would reasonably lead to bad times for these businesses.

therefore:
* anything that decouples the percentage/proportion from the actual number will be a weakener.

choice (a) is irrelevant, because nothing about the size of the number itself, either in absolute terms or in comparison to other states' numbers, matters -- we are only concerned with whether the number decreases.

choice (c) also has nothing to do with this argument, since tourists (and so, a fortiori, businesses catering to those tourists) are irrelevant -- the argument deals only with the interests of businesses that deal with retirees.
i.e., businesses dealing with tourists are no more relevant than businesses dealing with, say, children or disabled people.

[aanchalsinha]

I have 2 questions - regarding this particular qs and regarding argument type percentages vs numbers.

Regarding the above question, I chose E.

Since the question was based on the 3% stat, I figured the correct answer may revolve around the actual number of people who retired. So this thinking got me down to choices D & E. I picked E for the following reasoning,

conclusion: decrease in influx % --> -ve impact on eco of Florida
choice E: increase in people leaving --> -ve impact on eco of Florida

i.e. conclusion: A --> B
choice E: C --> B

I rejected choice D because it didn't talk about Florida.

regarding argument type percentages vs numbers

Is it safe to say that if the premise of the argument is based on percentages vs numbers,

for weakening qs: ans choice talking about actual numbers may weaken the argument as a whole. In other words it weakens the premise used as basis.

for assumption qs: ans choice talking about actual numbers must only kill the conclusion. If the conclusion is talking behaviour as opposed to the actual numbers this would be an incorrect choice. It would be much easier to explain this with regards to a particular qs which has been discussed here previously:
a-recent-report-determined-that-although-only-three-percent-t962.html

I would really appreciate your time. My test is in a week and I hope to get a response before that.

Thanks

[gmat.acer]

I also rejected(D) because it doesn't state "florida" explicitly.

Since OA is (D) & the question is from GmatPrep, it is clear that (D)'s description is about Florida - even though that's the only choice that doesn't have "florida" in it! How does this work? Do we just assume that because other choices talk about Florida, (D) also means its description is about Florida?

[jsummers]

Choice D need not talk about Florida. Question says that the %of people who retire and move to Florida is down by 3% and this decrease could affect economy.

Now assume that last year 1000 people retired and moved to another state. Out of these 1000 people, 100 of them move to Florida. That means, 10% of the people moved to Florida.

This year, the % of the people moved to Florida decreased by 3%. That means, only 7% of the total people moved to Florida.

Now, choice D states that the total number of people who retired and moved to other states increased significantly. Let us assume that a total of 10,000 people moved this year (where as it was 1000 people last year).

Now, 7% of 10,000 = 700 is the number of people who moved to Florida. Even though the % decreased, the actual number of people moved to Florida increased. This would weaken the argument.

[gmat.acer]

That makes sense. Thanks for clarifying jsummers !

[tim]

Glad to hear this explanation helped. Two quick things to keep in mind about CR:

1) Just because numbers are mentioned somewhere in the problem does NOT mean numbers have to be mentioned in the correct answer.

2) Just because Florida is mentioned somewhere in the problem does NOT mean Florida has to be mentioned in the correct answer.

Make sure you are actually analyzing what is going on in the argument rather than just blindly looking for the existence or absence of certain words..

[pratik.munjal]

Superb work jsummers! Awed by the use of numbers to explain the answer. That sort of a thing is Ron's "signature", but I guess there can be more than one geniuses everywhere! :)

[tim]

:)

[gbyhats]

Hi Dear Manhattan Instructors :)

What's wrong with choice E?

--

Because it is not the one that most seriously weakens the argument?

(which is shown in my example below: my example, while finally supports choice E, still supports choice D)

--

My example, largely borrowed from jsummers's, is follow:

First, assume that 10 years ago 1000 (+0) people retired and moved to another state. Out of these 1000 people, 100 of them move to Florida, while 100 of them move out Florida. That means, 10% of the people moved to Florida.

Then, last year, however, 1500 (+500) people retired and moved to another state. What's more, unlike 10 years ago, out of these 1500 people, 110 (+10) of them move to Florida, while 130 (+30) of them move out Florida. That means, 7.33% of the people moved to Florida.

And, the most important is that, a fact that support choice E, the number of people who left Florida last year > it was ten years ago.

[RonPurewal]

in general, if you're actually "plugging" specific numbers into a VERBAL problem ... don't. just don't do it.

there's a part of the test on which you're supposed to do that. it's called the quant section.

the point of statistics questions in the verbal section is to do exactly what you DON'T do in the quant section.
namely, two things:
1/ think about what the statistics mean (and what they don't mean)
2/ think about very general trends in those statistics

here, the general trends are ...
* the argument, about the success of businesses, is strongly correlated to the NUMBER of people (not to a percentage/proportion).
* the argument is about percentages.

the point of choice (d) is that, in general, choice (d) will make all the numbers bigger.
in other words-- if the base number is bigger, then "a decrease of 3 percentage points" does not necessarily mean a decrease! (in terms of symbols, (n-3)% of a bigger number could easily be more than n% of a smaller number.)

so, in general, choice (d) counteracts what we need for the argument to work. by looking at percentage points, we're assuming that we can compare percentages directly to numbers, and (d) precludes doing that.

[RonPurewal]

choice (e) is irrelevant because we're talking only about businesses whose clients are retired.

choice (e) talks about people who were NOT retired when they lived in florida, and then moved somewhere else to retire.
so, these people are irrelevant to the businesses in question. they were irrelevant while they were still in florida (since they weren't retired), and they were still irrelevant after retirement (since they weren't in florida anymore).

so, we just don't care about those people at all.