Automobile Dealers Advertisement: The Highway Traffic Safety Institute

As is often the case on GMAT CR, the key to this question lies in the language details.

The conclusion is that "the PZ 1000 is one of the safest cars available today."
The evidence is that "the PZ 1000 has the fewest injuries per accident of any car in its class."

Based on the evidence, the PZ 1000 might be one of the safest cars in its class, but does that necessarily make it one of safest cars available today?

PZ 1000 might be the safest within its class. But if it belongs to a particularly dangerous class, then PZ 1000 still might be more dangerous than most cars in OTHER classes.

Choice (C) tells us that PZ 1000 belongs to a particularly dangerous class, so it is the best answer.

I hope that helps!
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While reading through "Weaken question" section in powerscore CR bible , I came across common weakening scenarios. The book mentions that the following scenarios occur most frequently in this type of questions.

1. Incomplete information : The author relies on evidence which is weak and the conclusion can be weakened by bringing in new info.

2.Improper comparison : The author attempts to consider two or more items that are essentially different.

3. Qualified conclusion : The author qualifies or limits the conclusion in such a way as to leave the argument open to attack.

Now , I have come across questions of type 1(Incomplete info) , but i have rarely come across questions of other types . So would you please elaborate the 2nd and the 3rd type with the help of some questions.

I'll go with C. My reasoning:

If C is correct then PZ 1000 is more likely to be involved in an accident than a car from another class. And although the number of injuries per accident for PZ 1000 is low, the percentage of accidents it is involved in is high. Therefore, the number of injuries PER DRIVER-MILE can be high too and that is a good enough reason to believe that PZ 1000 is not the safest car OF ALL

OG-verbal review Q24 might qualify under "Incorrect comparison type"

Automobile Dealer's Advertisement:
The Highway Traffic Safety Institute reports that the PZ 1000 has the fewest injuries per accident of any car in its
class. This shows that the PZ 1000 is one of the safest cars available today.
Which of the following, if true, most seriously weakens the argument in the advertisement?
(A) The Highway Traffic Safety Institute report listed many cars in other classes that had more injuries per
accident than did the PZ 1000.
(B) In recently years many more PZ 1000's have been sold than have any other kind of car in its class.
(C) Cars in the class to which the PZ 1000 belongs are more likely to be involved in accidents than are other
types of cars.
(D) The difference between the number of injuries per accident for the PZ 1000 and that for other cars in its
54 class is quite pronounced.
(E) The Highway Traffic Safety Institute issues reports only once a year.

In this Ques, PZ1000, which has fewest inj/acci in it's class, is declared as one of the safest cars today. The argument "incorrectly" compares PZ1000 to all cars available today

For the "Qualified conclusion" type, I'm not too sure but Q50 (discussed here) in Verbal review seems like a match.
In this Ques, the author concludes that adequate moisture is essential for crop's survival and will result in prices falling sharply. This conclusion leaves the argument to attack with alternate causes, which may impact the crop's survival.

Can someone please explain this question Confused between Option C and D.

(C) Cars in the class to which the PZ 1000 belongs are more likely to be involved in accidents than are other types of cars. More accidents means more injuries even if injuries per accident are lower than for other vehicles.
(D) The difference between the number of injuries per accident for the PZ 1000 and that for other cars in its class is quite pronounced. Does not say if the PZ 1000 has more or less injuries per accident than other cars in it's class. The pronounced difference could go either way.

Conclusion of the argument:
The PZ 1000 is one of the safest cars available today.
Premise:
The Highway Traffic Safety Institute reports that the PZ 1000 has the fewest injuries per accident of any car in its class.

There are two assumptions that the author takes while stating the conclusion.
1. The class to which PZ 1000 belongs is the safest among all classes of cars.
2. The number of accidents that happen in PZ 1000 per number of PZ 1000 that run on the roads is substantially lower than any other car.
If either of these two assumptions are shattered we have the right answer.

The statement C attacks the second assumption and states that the PZ 1000 has lots of accidents and hence even though the number of injuries per accident are less but since the number of accidents are more its not really as safe as mentioned.

Hope this explanation helps

Hi akhil911,

I agree with your second assumption if we remove the word "substantially" from it.

However, I am not very sure about your first assumption. If the first assumption a must be true statement? What if we negate it? What if all other cars (which have the same category as PZ1000) are not very safe? Does that mean PZ 1000 is not the safest car? If none of the Indian cricketers can score more than 10,000 runs, does it mean that Sachin can also not do that?

-Chiranjeev
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W (Weaken): Conclusion PZ1000 is the safest car
Missing info : Is the class in which PZ1000 belongs to the safest class among all classes of cars?


(A) The Highway Traffic Safety Institute report listed many cars in other classes that had more injuries per accident than did the PZ 1000.
Actually supporting the conclusion to some extent.

(B) In recent years many more PZ 1000s have been sold than have any other kind of car in its class.
Irrelevant, as the premise made a point about safety in terms of injuries per accident and not total injuries or total accidents.

(C) Cars in the class to which the PZ 1000 belongs are more likely to be involved in accidents than are other types of cars.
Perfect Weakener. It says, the car belongs to ‘most accident prone’ category / class. So being safest in this category does not make it safest of all the classes

(D) The difference between the number of injuries per accident for the PZ 1000 and that for other cars in its class is quite pronounced.
Okay the difference is pronounced but on is it in favour of PZ1000 or against it ?
Half information ….Can’t help answering the question.

(E) The Highway Traffic Safety Institute issues reports only once a year.
Irrelevant.
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What do we mean when we say that the difference is quite pronounced??

D. The difference between the number of injuries per accident for the PZ 1000 and that for other cars in its class is quite pronounced.

As per my understanding, it means that there is quite a difference between the number of injuries per accident for the PZ 1000 and that for other cars in its class. So, it strengthens above conclusion.

Can someone comment on this?? I am not getting the actual meaning of this option? mikemcgarry

Dear vnigam21

I'm happy to respond. Like all official questions, this one is brilliant.

First of all, you are correct in the basic word usage. The word "pronounced" is an idiomatic intensifier with a few words, such as "difference." A "pronounced difference" is a fancy way to say "a very big difference" or "quite a difference."

We already know that the PZ 1000 has fewer accidents than other cars in its class, and (D) emphasizes this: it has many many fewer accidents than other cars in its class. Thus, it is really far and away the best in its class. But, that still leave the issue: how safe is this class of cars? If this is a class of the most accident prone cars on the road, then being the best in that class would not really be a ringing endorsement. Because we are doubt on this, (D) is not the strongest strengthener. By contrast, (C) nails this issue, and is the best answer.

Does all this make sense?
Mike
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I am convinced that option C is the best answer. But after going this thread what I can see is that most of the people have commented for option E is that its irrelevant.

(E) The Highway Traffic Safety Institute issues reports only once a year.

But as per my understanding its not irrelevant. It also slightly weakens the conclusion of the argument. But it is not as good a option as option C. Can someone comment on this option, in more detail? chiranjeev

Dear vnigam21,

I'm happy to help.

In connection with this question, I will recommend this blog article:
GMAT Critical Reasoning and Outside Knowledge
Students have the mistaken impression that all outside knowledge is irrelevant to the GMAT CR. Yes, very specific knowledge is irrelevant: in this case, we can't even have specific knowledge about the PZ 1000, because it's entirely a work of fiction. Nevertheless, it's very important to have a real-world business sense.

For example, how long does it take to redesign a car? What is the process from drawing board to released product available to consumers? If you plan to get an MBA, this is an excellent thing to know and understand, not only for cars but for all kinds of products. Business schools prefer that people walk in with these basic kinds of knowledge already, and the GMAT rewards such knowledge.

Generally, from design to finished product, for a car, takes 2-3 years. Toyota is an exceptional company: they can have something out and on the road in a year, which is simply mind-blowing.

OK, that's some relevant real world knowledge.

Now, let's look at this argument. The advertiser claims that the PZ 1000 is a safe as a kitten. What's wrong with this claim?

You say that (E) is not irrelevant.
(E) The Highway Traffic Safety Institute issues reports only once a year.

Are you imagining that the car's design might change, inside of year's time, from something very safe to something no so safe? Given the sheer time span that it takes to redesign a particular car, this seems irrelevant.

You see, outside general knowledge about how industries work is not so much helpful for getting the answer, but it does make the irrelevant information a little clearer.

Does all this make sense?
Mike
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Automobile Dealer's Advertisement:

The Highway Traffic Safety Institute reports that the PZ 1000 has the fewest injuries per accident of any car in its class. This shows that the PZ 1000 is one of the safest cars available today.

Which of the following, if true, most seriously weakens the argument in the advertisement?

(A) The Highway Traffic Safety Institute report listed many cars in other classes that had more injuries per accident than did the PZ 1000.
If other classes of cars have more # of accidents, then this option will strengthen the argument.

(B) In recently years many more PZ 1000s have been sold than have any other kind of car in its class.
Out of scope

(C) Cars in the class to which the PZ 1000 belongs are more likely to be involved in accidents than are other types of cars.
Correct. If this segment of cars are involved in more accidents, then PZ1000 can't be safer than other types of car. This argument is basically a causal type, since the author compares the # of accidents within a type of car and then proclaims it as the BEST amongst all cars. This option rightly compares the segment of cars to which PZ1000 belongs with the other segment of cars.

(D) The difference between the number of injuries per accident for the PZ 1000 and that for other cars in its class is quite pronounced.
This definitely strengthens the argument

(E) The Highway Traffic Safety Institute issues reports only once a year.
Out of scope

assume c is true-
100 accidents and 100 injuries so 1 injury per accident
80 accidents and 90 injuries - more than 1 injury per accident
so even if less injury per accident, we cant say its safe - is this reasoning correct(i doubt though! )

Official Answer:

Argument Evaluation

Situation An advertisement claims that the PZ 1000 is one of the safest cars available; it bases this claim on the Highway Traffic Safety Institute's report that this model had the fewest injuries per accident of any car in its class.

Reasoning What point weakens the advertisement's claim? Examine closely the difference between the report and the conclusion the advertisement draws from it. While the Highway Traffic Safety Institute compares the PZ 1000 to other cars in its class, the advertisement compares the PZ 1000 to all cars available today. What if the class of cars to which the PZ 1000 belongs is a more dangerous class of cars? In that case, while the PZ 1000 may the safest car of a dangerous class, it cannot be said to be one of the safest cars available.

Option C is the Correct answer. This statement properly identifies a weakness in the advertisement's argument.

Why are A, B, D and E wrong:-

A - The higher incidence of injuries per accident in other classes of cars supports rather than weakens the advertisement's argument.

B - The fact that the PZ 1000 is the best selling car in its class might be explained by the fact that it is the safest car in its class, but if this has any effect on the argument at all, it would be to strengthen rather than weaken it.

D - This slightly strengthens, rather than weakens, the argument.

E - The frequency of the reports is irrelevant to the advertisement's claim.
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Hi everyone! I thought this was a good question because the key to understanding this question has been tested many times before. People often use the saying, 'compare apples to apples', when trying to emphasize that you want to make appropriate comparisons. I've found this logic embedded in a few questions now so I thought I'd bring it up as a nice point to remember and essentially a key takeaway.

Also, I wanted to try and see if I could verbalize that while solving this question very quickly may rest on recognizing the heart of what is being tested, it is not the only way to do so. Even if you didn't recognize the 'apples to apples' comparison situation, there are other ways to find 4 wrong answers. I hope that this is helpful!


1. Read and compartmentalize - Very short and sweet prompt in the form of premise-conclusion. I am being asked to find a piece of information that points out a major flaw in the reasoning, and hence weaken the advertisement's argument.
2. Pre-think when possible - always! - If you've seen this type of question before, you were probably able to pick out that the safest model in class X does not necessarily mean the safest globally. However, if you did not, you can still work your way through these choices.
3. Find 4 wrong answers

(A) The Highway Traffic Safety Institute report listed many cars in other classes that had more injuries per accident than did the PZ 1000. - This answer choice actually does the opposite of what we want and supports the finding. If this answer choice is true, it strengthens the argument. So thank you, next, next.

(B) In recently years many more PZ 1000s have been sold than have any other kind of car in its class. - The statistic being quoted as evidence for the conclusion is presented on a per capita basis - "fewest injuries per accident" - so the volume of cars sold would not matter. Although it wouldn't be the most fairly conducted survey if you say surveyed 1 million PZ 1000s and 500,000 of all others, it does not weaken the argument

If you're not 100% clear on why this answer choice is inconsequential, let me see if I can try to provide a different perspective. Imagine that there is a boxing competition and there are 3 weight classes: Featherweight (122-126lbs), Welterweight (140-147lbs), and Light heavyweight (168-175lbs). Just because a competitor is the best fighter and i.e. winner in say, the Welterweight class, we wouldn't say that he/she is the best boxer today. It would always be qualified with he/she is the best 'Welterweight' boxer today.

(C) Cars in the class to which the PZ 1000 belongs are more likely to be involved in accidents than are other types of cars. Bingo! - If this model belongs to a group of cars that are more likely to be involved in accidents - i.e. is the best among potentially the worst - then it would likely be a stretch to conclude that it's one of the safest cars out there.

(D) The difference between the number of injuries per accident for the PZ 1000 and that for other cars in its class is quite pronounced. - "Quite pronounced"? What does that even mean? It could swing both ways, both in favor of the PZ100 and in opposition to.

(E) The Highway Traffic Safety Institute issues reports only once a year. Whether the HTSI ('Highway Traffic Safety institute') issues reports annually, semiannually, monthly etc. the frequency of publication will not help us have any implication on whether a car with the fewest injuries per accident in a class is necessarily the safest car out there.

Noteworthy: Here is a link to a question where recognizing the same logic is at the heart of solving the CR question.
https://gmatclub.com/forum/at-churchill ... 45355.html
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VeritasKarishma GMATNinja Need your help in this question.

For Option (C), I do not like it for the following reasons:
- Argument talks about PZ 1000 to be the safest car, and arrives on this conclusion using the number of injuries per accident.
- But the option (C) is more about how many PZ 1000 cars met accident but that still does not actually impact the safety at all. Because no of accidents could have been because of the drivers fault. or may be because there are already too many PZ 1000 cars on roads that the proportion of accidents might be same as others.

Premise: PZ 1000 has the fewest injuries per accident of any car in its class.

Conclusion: This shows that the PZ 1000 is one of the safest cars available today.

The data is based on comparison within its class. The conclusion talks about "safest cars available today". Think about the case where PZ1000 is a small car. What if full sized sedans are far safer than all small cars. Based on given data, can we say that PZ1000 is one of the safest cars available today? No.

(A) The Highway Traffic Safety Institute report listed many cars in other classes that had more injuries per accident than did the PZ 1000.
Helps our argument in a small way.

(B) In recent years many more PZ 1000s have been sold than have any other kind of car in its class.

Irrelevant. The data talks about injuries per accident. More or fewer cars is irrelevant.

(C) Cars in the class to which the PZ 1000 belongs are more likely to be involved in accidents than are other types of cars.

Correct. What if the cars of this class are more dangerous than cars of other classes. PZ1000 may be the safest car in its class but does it becomes one of the safest cars? No.

(D) The difference between the number of injuries per accident for the PZ 1000 and that for other cars in its class is quite pronounced.

Again, helps us in a small way.

(E) The Highway Traffic Safety Institute issues reports only once a year.

Irrelevant

Answer (C)
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