Partoria, large trucks - CR

[singh.ashutosh]

In the nation of Partoria, large trucks currently account for 6 percent of miles driven on Partoria's roads but are involved in 12 percent of all highway fatalities. The very largest trucks—those with three trailers—had less than a third of the accident rate of single- and double-trailer trucks. Clearly, therefore, one way for Partoria to reduce highway deaths would be to require shippers to increase their use of triple-trailer trucks.

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

A) No matter what changes Partoria makes in the regulation of trucking, it will have to keep some smaller roads off limits to all of larger trucks.
B) So far only the best, most experienced drivers for Partorian trucking companies have been driving triple trailer trucks.
C) Very few fatal collisions involving trucks in Partoria are collisions between two trucks.
D) In Partoria, the safety record of trucking industry as a whole has improved slightly over the past ten years.
E) In Partoria, the maximum legal payload of a triple-trailer truck is less than three times the maximum legal payload of the largest of the single trailer trucks.

Source GMAT Prep

OA - B

My first question is that the author here says the triple trailer trucks are involved in less than 1/3rd road accidents as compared to single and double trailer trucks which would mean that triple trailer trucks are involved in fewer accidents than average to single and double trailer truck ( Suppose single and double trailer trucks are involved in 300 accident then their average is 150 accident/truck where as triple trailer truck is involved in third of the total i.e. 1/3*(300) = 100) then why does author in the last line say the that best way to reduce deaths it to reduce shippers to increase their use to triple trailer truck, which according to the passage is involved in fewer number of accidents.
Also, how can be the correct choice. I can't really understand. Please explain.

Thanks

[george.kourdin]

hey

3 things

1) think there is a typo in the last sentence in the question stem. it makes little sense.
2) do not question the information given as in how can X be true. it may or may not be true, but the author of the passage/argument sincerely does believe that it is true and that the argument is valid. the author can literary write a paragraph saying that "cows have black and white spots. so do dalmatians, therefore they are related and are the same species." this is obviously wrong, but whether you or i agree with the authors conclusion is irrelevant.
3) i am just going to assume that there is a typo in the last sentence and the conclusion of the argument is "we should use more triple trucks because they have a lower accident rate than that of single and double trailer trucks".

increase use of triple trucks -> reduce accident rate on the roads

to weaken the argument find the conclusion and the premises supporting the conclusion.

if the conclusion is that A causes B we can weaken it if we show that:

some other factor other than A causes B
some other factor causes both A and B
relationship is reversed and B causes A
A and B are independent of each other and causal relationship does not exist (~relationship is coincidental)
there is a problem with the data presented

exciting right?

anyways so the argument is saying that triple trucks will reduce highway deaths. (B) is basically saying that the drivers are amazing. whenever they are not driving trucks, they are racing F-1 cars. what does that mean? this means that its not really the triple trucks that are tied to lower accident rates, it is the drivers. in other words, the shape/form/size of the truck has little to do with the accident/death rate. at least a portion of it is attributed to the driver. go back to conclusion: we said that triple trucks are the sole cause of lower accident rates. (B) is saying that there is another element present that causes low accident rates.


The END

[vivek.bs2010]

I was rushing through answer choices, so I didn't notice (B). Still, wouldn't you agree that (E) weakens the argument too?

Arg -> increase use of triple trucks.
Problem that the argument causes, if option (e) is true -> maximum capacity of triple truck is less than 3 times the capacity of a single truck. Shippers will not want to reduce profits by carrying lesser payload, and so, will not increase the number of triple trucks.

Am I going way off base here?

[RonPurewal]

I was rushing through answer choices, so I didn't notice (B). Still, wouldn't you agree that (E) weakens the argument too?

Arg -> increase use of triple trucks.
Problem that the argument causes, if option (e) is true -> maximum capacity of triple truck is less than 3 times the capacity of a single truck. Shippers will not want to reduce profits by carrying lesser payload, and so, will not increase the number of triple trucks.

Am I going way off base here?

the argument is that an increase in the use of triple-trailer trucks, if implemented, would make the highways safer. the forces promoting or inhibiting that change are irrelevant; the argument is only about what would happen if that change actually came to pass.

analogy:
if i lose weight, i will be able to run faster.
--> if you say "it will be difficult for me to lose weight", that would not weaken this claim.

[vivek.bs2010]

the argument is that an increase in the use of triple-trailer trucks, if implemented, would make the highways safer. the forces promoting or inhibiting that change are irrelevant; the argument is only about what would happen if that change actually came to pass.

analogy:
if i lose weight, i will be able to run faster.
--> if you say "it will be difficult for me to lose weight", that would not weaken this claim.

Got it.
Thanks Ron!

[RonPurewal]

sure

[aliassad]

Hi,

Sorry for reopening an old thread. In this question there is a scope shift

Premise 1 : trucks currently account for 6 percent of miles driven on Partoria's roads but are involved in 12 percent of all highway fatalities


Premise 2: The very largest trucks those with three trailers had less than a third of the accident rate of single and double trailer trucks


Conclusion: One way for Partoria to reduce highway deaths would be to require shippers to increase their use of triple trucks.

Now the second premise shifts subtly towards the accident rate and does not mention fatalities whereas the conclusion once again talks about fatalities


So if there were another option which would say that the triple trucks cause more serious accidents leading to more fatalities would this also weaken the argument?

Secondly, is it a good strategy to make prediction of an answer on strengthen/weaken questions?

I made prediction of an answer but was a bit flummoxed when I could not find my anticipated answer among the options.

Thanks in advance.

Ali Asad

[RonPurewal]

So if there were another option which would say that the triple trucks cause more serious accidents leading to more fatalities would this also weaken the argument?

yes, that would also weaken the argument. this is good thinking; it shows that you're thinking flexibly and aren't trying to memorize "rules". good for you.

unfortunately, it's not the answer that the authors of this particular problem chose. but, would it weaken the argument if it were there? yes it would.

Secondly, is it a good strategy to make prediction of an answer on strengthen/weaken questions?

maybe.

if making a prediction will render you blind to other possibilities -- in other words, if it will make you look only for your prediction, closing your mind off to other potential answers -- then, no, you shouldn't do it. (case in point: this problem.)

there's also a time issue. if timing is a problem on verbal, then you shouldn't bother predicting your own answers for S/W questions -- just go through the choices and evaluate the effect of each.
if you have some extra time, on the other hand, you may want to try. just be aware that, even if your choice is a potentially correct answer, it may be radically different from what is actually chosen by the authors of the problem.

I made prediction of an answer but was a bit flummoxed when I could not find my anticipated answer among the options.

if this makes you "flummoxed", then, as i've stated above, you should avoid making predictions in the future.

after all, there are almost always six million zillion ways to weaken any particular argument, so it's folly to expect any particular one of them.
for instance:
my friend, whose body weight has been constant for years, has started eating more food than ever before. therefore, she's going to gain weight.
there are tons and tons of ways to weaken this argument. e.g.:
she's exercising more now.
she's eating more food, but the food is leaner and less calorie-dense.
she has started taking a medicine that speeds up her metabolism.
she has a disease that is causing her body to waste.
etc.
it would be unwise to expect any particular one of these answers, since any of them would be a weakener.

[aliassad]

Thanks Ron for all the replies.

Your explanations are amazing and your words are worth their weight in gold.

[thanghnvn]

Thankk you Ron,
I see you and other expert advise us to
-prethink an assumption
-prethink a weakener which invalidate this assumption
before going to answer choices.

the above step help us
-better understand the argumen
-better analyse the answer choices, even when the assumption and its weakener prephrased are not what we see in the correct answer.

I apply the above process I see effective.
I wish you to detail your process of doing this question so that we can imitate.

[jlucero]

thanghnvn- I think Ron did that in his first post. If you have a specific question about his reasoning, let us know. Otherwise, let us know how you reasoned it and we can help you with where you go right or wrong.

[Khush]

Though I chose A, I am unable to understand why is E incorrect.

Issue in the passage is whether the increased use of triple trailer trucks on highways will reduce highway deaths.

Choice A weakens the force of reasoning by giving the credit of lower accident rate to the small traffic of the highway.

Doesn't E also weaken the force of evidence by showing that lower payload of triple-trailer trucks is responsible for the lower accident rate on highways?

Please help me understand the reasoning here.

[NL]

This question was earlier posted on the forum but the guy made at least 10 mistakes in typing the problem. sic Ron

This mistake (the bold guy) adds up to 11. Should we have the 3rd thread?

[RonPurewal]

.

[siddhartha.sylloge]

Attributing fewer accidents to three trailer trucks, author has assumed that replacing one or two trailers trucks with three trailers tucks will reduce the number of accidents. Option B relates the fewer accidents relationship with experience of driver.