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weaken the argument----lsat

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weaken the argument----lsat

by thephoenix » Thu Apr 01, 2010 8:56 pm
Over the last 25 years, the average price paid for a new car has steadily increased in relation to average individual income. This increase indicates that individuals who buy new cars today spend, on average, a larger amount relative to their incomes buying a car than their counterparts did 25 years ago.
Which one of the following, if true, most weakens the argument?
(A) There has been a significant increase over the last 25 years in the proportion of individuals in households with more than one wage earner.
(B) The number of used cars sold annually is the same as it was 25 years ago.
(C) Allowing for inflation, average individual income has significantly declined over the last 25 years.
(D) During the last 25 years, annual new-car sales and population have both increased, but new-car sales have increased by a greater percentage.
(E) Sales to individuals make up a smaller proportion of all new-car sales they did 25 years ago.

having a tough time to crack this
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by Phirozz » Thu Apr 01, 2010 11:28 pm
C is the answer
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by reply2spg » Mon Apr 05, 2010 6:30 pm
C is good here. please let us know the OA
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by subgeeth » Tue Apr 06, 2010 6:09 am
IMO E-Tough one
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by suchoudh » Tue Apr 06, 2010 6:26 am
IMO E.
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by GMAT680 » Tue Apr 06, 2010 7:21 am
IMO - E
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by paddle_sweep » Sun Apr 18, 2010 11:16 am
I think it's E but please confirm the OA.

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by reply2spg » Wed Apr 21, 2010 12:26 pm
Is it A. I guess A is the only one weakens the argument. C strengthen the conclusion. What is the OA?
thephoenix wrote:Over the last 25 years, the average price paid for a new car has steadily increased in relation to average individual income. This increase indicates that individuals who buy new cars today spend, on average, a larger amount relative to their incomes buying a car than their counterparts did 25 years ago.
Which one of the following, if true, most weakens the argument?
(A) There has been a significant increase over the last 25 years in the proportion of individuals in households with more than one wage earner.
(B) The number of used cars sold annually is the same as it was 25 years ago.
(C) Allowing for inflation, average individual income has significantly declined over the last 25 years.
(D) During the last 25 years, annual new-car sales and population have both increased, but new-car sales have increased by a greater percentage.
(E) Sales to individuals make up a smaller proportion of all new-car sales they did 25 years ago.

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by chrsrook » Wed Apr 21, 2010 2:52 pm
IMO A.

I don't think C is correct - if the individual income has declined, then the % of income that needs to be spent to buy a car would be more, which is what the conclusion is as well.
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by Testluv » Wed Apr 21, 2010 7:24 pm
having a tough time to crack this
Weakeners attack the assumption while strengtheners back the assumption up. Thus, the Kaplan method for stn/wkn questions involves first identifying the assumption.

But when the the assumption is reasonable and makes commonsense, it may be difficult to identify. (This is because we don't often get rewarded for being unreasonable or for defying commonsense!).

So, when we are dealing with an argument that seems to make perfect sense, in order to figure out the assumption, we should think hard about how we can disprove that argument (and you should do this looooong before you even think about going to the answer choices).

This argument, at first brush, seems to make perfect sense. After all, if the average price in relation to average income has gone up, that sure does seem as though (new) cars are now more expensive. So, how can we disprove the argument?...Well, the author never did prove that average income has gone up; that would be an assumption on hs part (and possibly ours).

What if average income has gone down?

Looking at it mathematically:

The author thinks that:

"because the fraction (new car)/(income) has gone up that the numerator (new car) must have gone up".

But that's not necessarily the case, as the denominator (income) could have gone down. So, he is assuming that it hasn't. Choice C directly attacks this assumption by telling us that it has. Thus, choice C is a weakener.

Choose C.

________

This argument (even if it is an LSAT argument) is a good reminder that:

--CR often likes to test quantitative reasoning

--we should always paraphrase arguments ("because of x, y")

--we should work with the stimulus, generate a prediction and aggressively scan for a match, rather than over-using POE (wrong answers are written to be seductive)

--we should be RUTHLESS with the author. By this I mean we give the author his stated evidence and nothing else. We figure out what the author's evidence establishes, "give" him all of that but nothing more. In this question, the more ruthless (less generous) with the author you are the more quickly you recogniz that he never proved income went up--and the more likely you are to see the importance of that.

__________

Quickly considering choices A and E, the other two that were discussed:

Choice A is irrelevant. The argument was about "individuals" that buy cars not households that do.

Same for choice E. For the author's argument it doesn't matter whether sales to individuals make up a large, expanding or small, shrinking proportion of all new car sales. His argument that individuals are now spending more on cars (in relation to their income) can stand either way.
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by xyztroy » Thu Apr 22, 2010 8:03 am
Testluv wrote:
having a tough time to crack this
Weakeners attack the assumption while strengtheners back the assumption up. Thus, the Kaplan method for stn/wkn questions involves first identifying the assumption.

But when the the assumption is reasonable and makes commonsense, it may be difficult to identify. (This is because we don't often get rewarded for being unreasonable or for defying commonsense!).

So, when we are dealing with an argument that seems to make perfect sense, in order to figure out the assumption, we should think hard about how we can disprove that argument (and you should do this looooong before you even think about going to the answer choices).

This argument, at first brush, seems to make perfect sense. After all, if the average price in relation to average income has gone up, that sure does seem as though (new) cars are now more expensive. So, how can we disprove the argument?...Well, the author never did prove that average income has gone up; that would be an assumption on hs part (and possibly ours).

What if average income has gone down?

Looking at it mathematically:

The author thinks that:

"because the fraction (new car)/(income) has gone up that the numerator (new car) must have gone up".

But that's not necessarily the case, as the denominator (income) could have gone down. So, he is assuming that it hasn't. Choice C directly attacks this assumption by telling us that it has. Thus, choice C is a weakener.

Choose C.

________

This argument (even if it is an LSAT argument) is a good reminder that:

--CR often likes to test quantitative reasoning

--we should always paraphrase arguments ("because of x, y")

--we should work with the stimulus, generate a prediction and aggressively scan for a match, rather than over-using POE (wrong answers are written to be seductive)

--we should be RUTHLESS with the author. By this I mean we give the author his stated evidence and nothing else. We figure out what the author's evidence establishes, "give" him all of that but nothing more. In this question, the more ruthless (less generous) with the author you are the more quickly you recogniz that he never proved income went up--and the more likely you are to see the importance of that.

__________

Quickly considering choices A and E, the other two that were discussed:

Choice A is irrelevant. The argument was about "individuals" that buy cars not households that do.

Same for choice E. For the author's argument it doesn't matter whether sales to individuals make up a large, expanding or small, shrinking proportion of all new car sales. His argument that individuals are now spending more on cars (in relation to their income) can stand either way.

Question is not taking about the Ratio as you mentioned in your reasoning: fraction (new car)/(income)

Q is talking about the % of individual's income (fraction) spent on cars:
I think answer should be E.
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by Testluv » Thu Apr 22, 2010 11:02 am
hmmmm...

Yes, this question's wording is very tricky, and perhaps ambiguous....I misread it the first time. I'm going to change my mind here to choice E also!

The author is arguing that because the price paid for new cars has risen in relation to average income that individuals who buy new cars now spend, on average, a greater amount in relation to their income. So, the evidence involves a comparison of statistics. But we don't know what caused the increase in price paid for new cars. It could be that families or companies are now buying far more expensive cars (while individuals are not), and that this is what caused the average price for cars to go up. In other words, this argument involves a shift in scope.

Choice E attacks this assumption, and must be correct.

Thanks to Kevincanspain for pming me, arguing that choice E was correct.
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by EricJA » Fri Sep 28, 2012 6:57 pm
The question is about the proportion of an individual's income spent on a car and the argument says that now we spend more as a proportion than we did 25 years ago. None of the choices is relevant except the one about more two income homes. Imagine that each wage earner in the house made 30k and they bought a car for 15 and that is the average. Let's say 25 years ago, one wage earner made 15k and bright a car for five k and that was average.

The modern folks each spent 25 percent of their income and the guy a generation ago spent a third of his.

Having two wage earners raises income but reduces the proportion spent on the car. The rest of the choices don't come close to weakening the conclusion that modern people spend a greater percentage of their income on cars.

If average income fell and all else stayed the same, the average person would spend more on a car, so C strengthens the argument.

E is totally irrelevant. Who cares what proportion of cars were sold to inviduals. The argument is about whether the individuals spent more of their total income on the cars. A is right. [/quote]
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by akashkumar1987 » Sat Sep 29, 2012 7:11 am
Answer is A
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