Studies have shown that a large percentage of car accidents are caused

Question

Studies have shown that a large percentage of car accidents are caused by aggressive driving. To help reduce the number of accidents and to promote traffic safety in general, insurance companies have begun to issue discounts to drivers who take defensive driving courses. Research shows that people who practice defensive driving are considerably less likely to get into a car accident. Therefore, the insurance company’s plan should help reduce the number of accidents.

Assuming the statements above are true, which of the following can be inferred from them?

A. The majority of accidents are caused by drivers who possess insurance.

B. People who manage to consistently avoid car accidents are likely practicing defensive driving.

C. Young males and other demographics known for disproportionately being involved in car accidents are less likely to practice defensive driving than other demographics.

D. An individual who does not practice defensive driving is always more likely to get into a car accident than an individual who does practice defensive driving.

E. Discounts are the most effective way for insurance companies to promote defensive driving.

GMATPill · Accepted Answer

GMATQuant25,

It looks like you are a GMAT Pill student. Let's go ahead and tackle this with Framework #8 Inference. In the process, you'll see the concept from Framework #4 Negation play a role as well.

Framework #8 Inference

So you immediately you identify this question as an INFERENCE question. That means, do not be confused and take an answer choice and try to make it support the conclusion that is mentioned in the last line of the passage. That would be WRONG. If you did that, you're finding an ASSUMPTION -- not an INFERENCE.

So with inference questions, you take an answer choice -- and you ask why is that statement true? Is it true because... (then some detail in passage that might support THAT answer choice as being a valid conclusion --- as opposed to a valid assumption).

Let's look at (C)

C. Young males and other demographics known for disproportionately being involved in car accidents are less likely to practice defensive driving than other demographics.

Why would that be a valid conclusion? How do we know that...."guys and those who get into car accidents are LESS likely to practice defensive driving?

The reason is because...

Anything from passage to help us out? Well the passage doesn't talk about "young males". But it does have something about the types of people that get into car accidents. Well, it talks about those who get into FEWER accidents -- hmm that must be the negated version since the argument was about those who got into MORE accidents. Let's elaborate.

Now, negation is an important concept on GMAT CR. So immediately, you should think...can I use the negated example from the passage to support my claim?

So what is in the passage? Can it be said to be the "negated" form that would actually help support the claim?

Well, passage says those who DO practice are LESS likely to get into accidents.
So let's rewrite that:

Argument:  Those in accidents a lot do not practice defensive driving
 Basis:  DO Practice defensive driving => LESS likely in accidents

We know with Framework #4 Negation -- one method of supporting the argument is by showing the negation of that argument to be true. In this case, that's exactly what we do.

We take this basis (sourced from passage) and we negate it.
 Basis:  DO Practice defensive driving => LESS likely in accidents
 Negated Basis:  DO NOT practice defensive driving => MORE likely in accidents.

OK, does his negation support the argument?

Argument:  Those in accidents A LOT do NOT practice defensive driving (answer choice C)
 Negated Basis:  Those who DO NOT practice defensive driving => MORE likely in accidents.

Clearly we see the negated basis is SUPPORTING the argument now.

(C) says some group that gets into A LOT of accidents does not practice. In other words, these types of people do NOT practice and get into A LOT of accidents. This is exactly what our negated basis is helping us say.

Thus we managed to take information in the passage ("practice defensive driving =>less likely in accidents")
and use that to support our inferred statement (those who "DO NOT Practice defensive driving => MORE likely in accidents") by negating the basis found in the passage and observing how it SUPPORTS the claim made in answer choice (C).

ChrisLele · Answer

My answer is (C).

Let’s first look at answer choice (B) and why it is incorrect:

Essentially, this answer choice is saying that people who practice defensive driving are likely to avoid accidents. However, those who in general avoid accidents could be doing so for a variety of reasons, i.e. defensive driving isn’t the only way to avoid accidents. (You can think of those who avoid accidents as a large circle or which defensive drivers are only a small circle within this large circle).

So let’s say 90% of people who avoid accidents do so because of something besides defensive driving (e.g. they get their brakes tested). If this is the case, then (B) is invalidated, because the people who are consistently avoiding accidents are not necessarily practicing defensive driving.

As for answer (C), though it may seem “out of scope” because it mentions demographics not found in the prompt, inference questions can pertain to information outside the passage. As long as the statement can be inferred based on the information in the passage.

In this case, “those who practice defensive driving are considerably less likely to get into a car accident” does not include young male/other demographics. This group, based on the information in the passage, is likely to get into a car accident. Therefore, young males/others are less likely to practice defensive driving.

georgepaul0071987 · Answer

A is irrelevant , E and D are a bit too strong . B is the converse of what you infer from the passage . C is correct because it is the contrapositive . Always remember the converse and the inverse of the statement may or may not be true , but the contrapositive will always be true .

Posted from GMAT ToolKit

https://gmatclub.com/static/posted_from.png     Posted from    GMAT ToolKit

mikemcgarry · Answer

Dear navneet001 , I'm happy to help. :-)

First of all, when you have a question about a specific question of a particular type, I would recommend posting it in the part of the forum devoted to that question type. For example, I believe this question would have been most appropriately posted in the Critical Reasoning section of the Verbal Forum. In this question, (D) lays a trap, a very tempting trap, and I'm sorry to say, you fell for it hook, line, and sinker. Many folks who have not studied statistics in depth would fall for this mistake. You see, let's think about the statement --- in the general population, quality A is correlated with quality B. As a overall, general rule, individuals with a higher degree of A (whatever that is) also have a higher degree of B. Correlations and related trends speak to something that is true in the population-wide view. BUT, we must keep in mind, correlation does not imply causality, so if we go down to the level of the individual, we can't say if person #1 has more A than person #2, then person #1 must also have more B. Correlations are about whole population trends and may not play out at the granular level. For example, there's a well-measured correlation between height and salary --- tall people, on average, are somewhat more likely to have a high salary than short people. Nevertheless, it's trivially easy to find examples of individuals who are short & rich or tall & poor. The correlation only speak to a pattern that emerges when we have a "whole population" view, and this pattern may be weak or virtually indiscernible at the individual level. That the problem with (D) ---- it takes the pattern that true as an overall population-wide trend and tries to concretize it at the level of one individual compared to another. Does this make sense? Mike :-)

Khalidb · Answer

This argument contains a conditional statement. If people are less likely to get into a car accident, they are more likely practicing defensive driving. The contrapositive of that is if people are less likely practicing defensive driving, they are more likely to get into a car accident. So answer C is the correct one.

navneet001 · Answer

Hi Experts,

I am just a beginner, so please pardon if I did not frame/format the question correctly. 
I came across below question (attached the screenshot), please let me know if I should type it in:

The solution suggested is option C. I am confused on why Option D is not correct. It clearly says that the 
‘Research shows that people who practice defensive driving are considerably less likely to get into a car accident.

Is not option D stating exact the same ?

Thanks in advance.

gmatquant25 · Answer

GMAT PILL instructors - Could you please explain me how to tackle the question using your strategy ?

Nevernevergiveup · Answer

aggressive driving causes a large percentage of car accidents.

People who practice defensive driving are considerably less likely to get into a car accident. 
 (Aggressive driving behaviors do not practice defensive driving)

Therefore, the insurance company’s plan should help reduce the number of accidents.

Assuming the statements above are true, which of the following can be inferred from them?

A. The majority of accidents are caused by drivers who possess insurance. 
 (Insurance is not mentioned at all. OFS)

B. People who manage to consistently avoid car accidents are likely practicing defensive driving. 
 (can be correct but those who in general avoid accidents could be doing so for a variety of reasons)

C. Young males and other demographics known for disproportionately being involved in car accidents are less likely to practice defensive driving than other demographics.
 (This is inline with our pre-line thinking and correct answer)) 
 
D. An individual who does not practice defensive driving is always more likely to get into a car accident than an individual who does practice defensive driving. 
 (This cannot be inferred as this is extreme case.)

E. Discounts are the most effective way for insurance companies to promote defensive driving.
 (Most effective-extreme case)

QuanVsVerb · Answer

The argument says:

Premise :
if aggressive driving, then more chance of an accident happening. AD--> AH, c ontrapositive A~H--> ~AD
if defensive driving , then less chance of an accident happening. DD--> A ~H , contrapositive : A H --> ~DD

Conclusion: if more people are defensive drivers, then less accident.

A. Out of scope. Out
B. People who avoid accidents are more likely to be driving defensively. Looks likes they are reversing the logic. A~H --> DD. Out.

C. Young people & some other demographics who constitute a majority of those involved in accidents are less likely to practice defensive driving.

Now , young people& some other demographics are a subset of those involved in accidents. 
that implies, if YP, then AH 
YP--> AH

Using syllogism, AH--> ~DD(from Premise), YP-->AH(from C) therefore YP--> ~DD. Yes!

D. Division Fallacy. Assuming what applies to the group applies to an individual. Out.
E. Out of scope. Out

Senthil1981 · Answer

C. Young males and other demographics known for disproportionately being involved in car accidents are less likely to practice defensive driving than other demographics.

They word with Young male, just as a trap, to make people think this is out-of scope. But read it , Young male and other demographics, which includes all basically.
So rewording, People known for disproportionately being involved in car accidents are less likely to practice defensive driving than other demographics.

Talayva · Answer

I have query regarding option C . Option C is correct , but it is grammatically incorrect making the choice ambiguous .
C. Young males and other demographics known for disproportionately being involved in car accidents are less likely to practice defensive driving than other demographics. -----
This option states that young people are less likely to practice defensive driving in future . However , the intended meaning is that they did not practice defensive driving and hence are likely to be involved in an accident

C. Young males and other demographics known for disproportionately being involved in car accidents are less likely to  HAVE  practice defensive driving than other demographics.

Usage of Have corrects this error.

My query is not regarding grammatical correctness , but the logic arising out of it.
 egmat  could you help me

pragya007 · Answer

Till now I am not able to reject option A because as insurance companies are offering a discount that means people must have taken insurance then only this whole process will able to stop the accident . So I can infer from the above statement that at least all the ppl who have to meet with an accident must have Insurance else this whole scheme wouldn't work.

Please help

Please help

CrackverbalGMAT · Answer

Hi Pragya

The problem with option (A) is with the word "majority".

You are correct in reasoning that the insurance companies' plan to offer discounts to drivers who take defensive driving courses will only help in reducing accidents among those who have insurance. However, this reduction is still a reduction in total number of accidents. We cannot be certain that among all the accidents caused, >50% will be by those with insurance.

Let us consider some example numbers.

Let us assume that 100,000 drivers purchase insurance and the number of accidents is 1000. While the insurance companies' plan to offer discounts will only reduce accidents caused by these 100,000 drivers, we cannot be sure whether this constitutes >500 or <500 of the 1000 accidents that are caused by  all  drivers. For instance, even if only 300 accidents are caused by drivers with insurance, the insurance companies' plan will work in reducing this 300 to, say, 250, which is still a reduction in the total number of accidents.

Hope this clarifies.

Crytiocanalyst · Answer

A. The majority of accidents are caused by drivers who possess insurance.
We are not so sure whether it was caused by insurance people or otherwise

B. People who manage to consistently avoid car accidents are likely practicing defensive driving.
This a possiblity however this being not secepted felt like a trap answer if none of them were making sense i would have chosen this

C. Young males and other demographics known for disproportionately being involved in car accidents are less likely to practice defensive driving than other demographics.
Yes this can be infered due to their severe recklessness the accidents are occuring

D. An individual who does not practice defensive driving is always more likely to get into a car accident than an individual who does practice defensive driving.
We are not absolutely sure about this too

E. Discounts are the most effective way for insurance companies to promote defensive driving.
We don't know whether this is the best option or one among the option

nidhijainn · Answer

KarishmaB   GMATNinja  can you please explain why is D the wrong choice?

KarishmaB · Answer

First notice that we are asked to assume that the statements given in the argument are true. So they are all premises even if the last statement looks like the author's conclusion.

Argument:

- a large percentage of car accidents are caused by aggressive driving. 
- Research shows that people who practice defensive driving are considerably less likely to get into a car accident.

Plan: Issue discounts to those who take defensive driving courses.
Target: To help reduce the number of accidents and to promote traffic safety in general

- Company’s plan should help reduce the number of accidents.

We need to find an inference now - something that must be true if all above statements are true.

A. The majority of accidents are caused by drivers who possess insurance.

Not necessarily true. Say if only 40% accidents are caused by drivers who possess insurance, even then the plan could reduce the number of accidents.

B. People who manage to consistently avoid car accidents are likely practicing defensive driving.

Not necessarily true. People avoiding accidents could have other good driving habits or skills.

C. Young males and other demographics known for disproportionately being involved in car accidents are less likely to practice defensive driving than other demographics.

We know that people practising defensive driving are considerably less likely to get into a car accident.
Demographics that have a high rate of car accidents then are less likely to be practicing defensive driving than other demographics. If they had been practicing defensive driving, they would have been less likely to get into a car accident because research tells us that. Demographics practising defensive driving are considerably less likely to get into a car accident.

D. An individual who does not practice defensive driving is always more likely to get into a car accident than an individual who does practice defensive driving.

Not correct. Two reasons for that. First, we are told about the group as a whole. There could be outliers. Someone could be practicing defensive driving but still having other risk factors (driving at night or on risky routes etc) which could make him/her more susceptible to an accident. Second, 'practicing defensive driving' generally makes an individual safer than before (when we compare him/her with himself/herself from before). He/she may still be at more risk than another individual who doesn't practice defensive driving but has other very good driving habits.

E. Discounts are the most effective way for insurance companies to promote defensive driving.

It needn't be "the most" effective way. It just needs to be effective.

Answer (C)

Angelia11 · Answer

C. I believe this is the right reasoning.

RiyaJ0032 · Answer

While your this part of the explanation is logical - those who "DO NOT Practice defensive driving => MORE likely in accidents"

however, the option is not that they are more likely to get into accidents
the option is that they are less likely to practice defensive driving, or that their probability of driving defensively is less compared to other demographic

we know those who are involved in accidents, they are not doing defensive driving

but we cannot say that the probability of these people to practice defensive driving is less compared to others

it can be that their probability to practice defensive driving after taking up defensive driving classes is just as same as others

and the classes have just begin recently

the accidents have been happening since past

we know that those who cause/are involved in accidents do not do defensive driving

but it can still be that they are just as likely to do it once they take up these classes

DmitryFarber , some help please!

DmitryFarber · Answer

RiyaJ0032  Yeah, this isn't a good question. C has some support, but it also has a statistical flaw.

First, you're right that we don't know what will happen when these people take a class, in part because we have no causal information. If defensive drivers get in fewer accidents, is it because of those strategies, or because of some other feature they share? (Maybe they are more cautious people in general, more experienced drivers, less prone to drive drunk, etc.)

However, we do know that overall, the group of people who use defensive driving gets in fewer accidents. If they NEVER got into accidents, we could reason like this: Defensive --> no accident. Therefore, accident --> NOT defensive. In other words, if defensive driving prevented all accidents, then by definition anyone who got in an accident must not have been using defensive driving. Since we just know that these drivers are LESS LIKELY to get into an accident, all we can conclude is that if someone gets in an accident, it is LESS LIKELY that they use defensive driving than if they had not gotten into an accident.

This still leaves a lot of room for variation, especially since we don't know the actual likelihoods. Nor do we know enough about the subgroups to see whether they might be exceptions to the general rule. To put this together, let's use an analogy that may feel close to home:

Premise: People who study intensively on gmatclub are considerably less likely to get a low score on the GMAT.

C) Groups who struggle with GMAT content, such as those with very limited English proficiency, are unlikely to study intensively on gmatclub. 
We can't infer this at all! We just know that as a group, people who study intensively on gmatclub tend to do well. But that's not a guarantee for everyone! As long as some people still don't do well, that could include entire groups who have obstacles in their way. Perhaps they don't benefit as much from gmatclub, or perhaps they do, but their starting point is much lower. For instance, if this month 1,000 people who studied intensively on gc take the test, all we know is that this 1,000 won't include nearly as many low scorers as a group of people who did NOT have this preparation. Maybe our group has only 70 low scorers, while the other has 300. But that 70 could include all those with very limited English proficiency.

Getting back to the original, maybe young males are only 15% of drivers, so they can be among those who DO get into accidents despite using defensive driving. And if there's a smaller group that represents, say, only .02% of drivers, then their accident rate won't tell us much about whether they use defensive driving.

Studies have shown that a large percentage of car accidents are caused

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Studies have shown that a large percentage of car accidents are caused

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