Reducing speed limits neither saves lives nor protects the environment

The no. of cars is not the issue. Its the emission & the safety that are important. So D & E are the sole candidates. But the problem with E is the use of word 'only' which is not stated in the argument. Hence D is the best.

question#1 - I have no issues with OA D. I actually chose that while answering this question. However, I am curious about A). Setting aside the main issue about environment and safety, I feel that A) hinges on a minor gap in the argument : Premise talks about "more slowly a car is driven .... " but the conclusion is about "reducing speed limit ". I feel that A) is trying to attack this gap. Essentially, just because the speed limits are reduced, the drivers won't have an incentive to drive slowly. If there are some drivers who don't follow the speed limits, then wouldn't this weaken the connection between driving slowly and speed limits --- drivers don't obey speed limits at all.

Also, I have also read in one of the CR notes floating in the forum that negation of sufficient conditions are generally out of scope.

question #2 -
to give an example :

Baseball players, who wear white shirt, always score a home run in their league matches.
Hence, Baseball players who wear white shirt help in winning the game.

If one of the answer choice says .."Baseball players who don't wear white shirt...." - it will be out of scope because we are only concerned about the sufficient condition - who wear white shirt.. However, I am trying to think - will there be any argument wherein the negation of sufficient condition could be in scope for an assumption/weaken or a strengthen problem? In other words, will there be an argument for which a condition like men who don't wear white shirts ....would be in scope. I am trying to think about such argument . Not sure whether OG has something similar.


Thanks

Honestly, I think at this point, you would be better off on CR, more successful and more efficient, if you purged the words "necessary" and "sufficient" from your mind.

Here the original argument:
Reducing speed limits neither saves lives nor protects the environment. This is because the more slowly a car is driven, the more time it spends on the road spewing exhaust into the air and running the risk of colliding with other vehicles.
Clearly, this is a statistical argument --- if most of the cars go slower, you will get these problems. There is no reality, real or imagined, in which every driver on the road drives exactly at the speed limit --- there will always be slower and faster drivers. The effect of setting a certain speed limit, or reducing the speed limit, is to move where the central hump of the bell curve of speeds falls. The fact that some drivers speed is in no way a "hole" in this argument.

The question asks:
The argument’s reasoning is flawed because the argument
We need a weakener, something that will undermine the evidence or assumption. Well, if a few select drivers are drive much faster than the speed limit, they place other slower drivers at risk --- the most dangerous condition is not uniform high speed, but larger differentials in speed. That actually strengthens the argument.

I guess the really big question is --- if you know what the right answer is, and have no problem with it, why are you dissecting wrong answers like this? Yes, it's important to understand why wrong answers are wrong, but it's not at all clear to me whether the level of attention you give to incorrect answer has not crossed the threshold of diminishing returns and whether it's now counterproductive in terms of efficiency.



OK, here I think there are some grammar points you don't understand, and they are befuddling the argument. Where you put the commas has big logical consequences. See these two posts:
https://magoosh.com/gmat/2012/that-vs-which-on-the-gmat/
https://magoosh.com/gmat/2012/gmat-gramm ... modifiers/

Also, the words you use to describe baseball are not idiomatically correct --- players don't "score" home runs, but rather "hit" home runs; and the contests are called "games", never "matches". The entire sentence is, in the context of baseball, completely unrealistic, so I will change it a bit.
Consider these two sentences:
a) Baseball players, who make a great deal of money, seem not to work very hard.
b) Baseball players who make a great deal of money seem not to work very hard.
Do you understand the logical difference in those two sentences? They say very different things.
The first is a comment about all baseball players, and attribute two things to all of them -- making a great deal of money and not working very hard.
The second is isolates a particular group of players, only those who make a great deal of money, and makes a comment specific to them.

Your first sentence was, "Baseball players, who wear white shirt, always score a home run in their league matches." That sentence implies, among other things, that all baseball players wear white shirts and that all baseball players are part of this discussion. Then, you ask about ."Baseball players who don't wear white shirt...." --- that would be an impossibility, given your first statement.

Whether you set off a modifying clause by commas from the rest of the sentence has huge logical implications for the meaning of the sentence.

Does that make sense?
Mike

Mike - You are correct, but I feel that finding why an incorrect answer is incorrect is really important. I was not clear about this answer choice. I wouldn't say that I considered this answer choice "incorrect" but "unsure." Hence, I wrote you a note. Now when I read this question again. I feel that the fact that some people exceed the speed limit will not weaken the argument because the argument doesn't impose such restriction. The argument uses a very mild language "the more slowly a car is driven...". It leaves open a possibility that someone may or may not exceed the speed limit.

Any thoughts on this one? I am eager to hear your opinion.



You are absolutely correct, Mike. I am sorry for that mistake. Now that you have pointed it out, I will not repeat it again. However, the reason why I wrote that question is still open. I was trying to come up with an argument in which the negation of the sufficient condition - in above case, "who wear white shirts" or noun modifier -- would be a correct answer. I read somewhere (I think Knewton Blog) that when the argument talks about, say, people who wear white shirts, be suspicious of the answers that talk about people who don't wear white shirts. Such answer choices are generally out of scope. However, my point was to know whether there *could* be an argument for which a strengthener/weakener or an assumption answer choice would be the negated version of the modifier. I am not trying to memorize anything here, but I am just trying to exercise my brain.

Essentially, the argument would talk about : people who wear white shirts.....

correct answer would be : people who don't wear white shirts....


Please let me know if you believe such a situation is possible.

Appreciate your thoughts and expert replies. They are really helping me.

Thanks

Thanks Mike. I guess I was curious to know whether negated sufficient condition 'could' be a correct answer for strengthen, weaken or an assumption question, and not just a weaken question. If you feel they could, please let me know. Thanks!

Let's say the argument is about "All people who do X are blah blah blah." Any answer choice that introduces people who don't do X --- in my experience, those are irrelevant distractors, never the correct answer on any GMAT CR questions.

Mike

Mike,
I recently read an article about Romney. How about this argument :

(Goal of the argument - demonstrate whether people who don't do X 'may' not be irrelevant)

Democrat - In my opinion, we need to increase the taxes on the rich because the deficits are already too high. By increasing the taxes, the government will be able to raise revenues, and hence fix the deficits.

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

A) If taxes are increased on the rich, the other class will be motivated to increase deductions, leading to the reduction in taxes paid by that class.
B) The rich are not willing to pay more taxes.

In my opinion, A) is a weakener even though it focuses on "the other" part -- not the rich. It's not out of scope or irrelevant. On the other hand, B) , though relevant to the conclusion, merely states wishes of the rich, which have not bearing on the reasoning.

Please let me know thoughts?

Thanks
Voodoo

This argument, as it is currently constituted, is not really up to GMAT standards for a good CR argument.



Neither one of these is anywhere near what the GMAT would consider a weakener. Deciding which one of these is best is like deciding whether it's better to build a house on a foundation of oatmeal or jello --- both are just plain bad, so no effort should be expended in the decision.

Mike

Mike,
Can you please explain why A) is not a good weakener, and the argument is bad? I borrowed this argument from one of the articles in NYTimes...... Please let me know your thoughts.


Thanks

Which of the following, if true, most weakens the argument?
A) If taxes are increased on the rich, the other class will be motivated to increase deductions, leading to the reduction in taxes paid by that class.
B) The rich are not willing to pay more taxes.
[/quote]

Mike,
Can you please explain why A) is not a good weakener, and the argument is bad? I borrowed this argument from one of the articles in NYTimes...... Please let me know your thoughts. [/quote]

Voodoo: you have to understand. GMAT constructs CR argument according to an exceedingly high standard. If you just rephrase an argument out of the newspaper, you are not automatically going to meet those standards. This argument is not necessarily a "bad" argument in terms of being illogical or obviously flawed. In the real world, it's a credible argument. It's just far too simple, far too simplistic, for the GMAT. The GMAT constructs arguments that are far more complicated, far more nuanced. There are explicit statements as well as finely honed implications. There are all sorts of standards of subtlety. My friend, I'm sorry to say this, but you simply do not understand these standards at all. In fact, you don't really need to understand how to *write* CR questions, just how to analyze and answer them. It's just an extremely poor idea for you to try to write you own CR example arguments.

As for (A) --- I don't know where to begin. It is a patently illogical and unrealistic statement. Most people with any sense already take the maximum allowable deductions they possibly can take: that is true across all brackets --- virtually no one with any brains pays more in taxes than they absolutely have to. It's ridiculous to think that any large number of people out there have left aside extra deductions that they could have taken, but have not yet taken, and will not take unless "provoked" by some new situation. Furthermore, if taxes are raised on the extremely rich, if anything, I think most of the so-called 99% would be happy, if not elated. That's not the sort of thing that would engender a panic along the lines of "I have to save every penny myself" among those who were not hit with the tax. It's a completely unrealistic motivation, which prompts them to take a completely unrealistic action.

Once again, you are not a good CR question writer or answer choice writer. Writing CR questions is a level of expertise far above analyzing and answering them. The best questions are written by people who regularly score in the 99th percentile on the GMAT. I understand you aspire to high standards, and that truly laudable, but you need to recognize your current limitations. You are preparing for the GMAT, not already a master of the GMAT. I would strongly recommend: give up the practice of trying to write credible CR questions --- it's beyond you. Stick to the analysis of questions from reputable sources (OG, MGMAT, Magoosh, etc.). If you are successful answering CR questions from legitimate sources, that is all the success you need at this particular moment in your life.

Does all this make sense?

Mike

Mike,

Thanks for your honest opinion. I know that I am not a good GMAT test writer. However, I believe that the reason why I posted that example was to test my understanding. I may not have been able to come up with a good example, but that shouldn't stop us from doing an analysis. As the great GMAT gods require us to assume, in many cases such as RC, CR and SC, that stated passages or premises are FACTs even though they may not hold good in real life. In fact, I remember one of the CR question in GMATPrep actually says that the $ rate and skills are completely independent. Even though, this is counter-intuitive in the industry (Just out of curiosity, I did a case study on this in my firm to check whether my intuition is actually correct! 29 out of 30 people, including graduates from top elite schools, said that $rate and skills are correlated.). One gets paid depending on the skills. A math Ph.D. from MIT gets better paid than a graduate from not-so-good or do-not-know-the-name-of university. (Research scholars are exception). However, I know a lot of researchers who are paid better than me. I agree with your opinion that I am not a good writer. I am sorry for coming up with a bad example.



This is not true from my real life experiences. Let me explain how. A lot of people in my department recommended that we utilize the benefits of technology and help people save some money on taxes by increasing deductions and by reducing the number of job cuts. For instance, two of my colleagues (there are actually thousands of such people), increased their deductions for this tax year because #1- they do car pool and #2 they work remotely from NJ as opposed to working physically in NYC. They don't have to go to offices in NYC, and hence no need to pay NYC taxes. There are a lot of people in financial industry who have taken some *green* steps to increase their deductions. Some people's wives have enrolled in graduate course - it helps them to save taxes, and wives have a better prospect of getting jobs. What provoked this? 2 things - bad financial results of companies and an increasing drive to cut costs by reducing labor and salaries. I am sorry for not being able to articulate the answer choice in a good way, but I believe that you might have got an idea of what was in my mind. I request you to assume that on same alien planet, say the GMAT, deductions could be changed.


That said, can you please let me know your thoughts? I think that the goal of our conversation was to come up with an argument in which the conclusion talks about people who do XYZ and the correct answer choice talks about people who don't do XYZ. It will be great if you could guide me. If you feel that this conversation is not worth our time or for any one reading this thread, then I will let it go.

Thanks again for your help. Awaiting your expert response.....

Again, in my experience of the GMAT, this does not exist. If the argument, and especially the conclusion, focus on people who do X, then any answer choice about people who don't do X is just a distractor, an incorrect answer choice. That's my sense from OG questions.

Why C is wrong. Could somebody explain ?

The argument is as follow: reducing speed limits neither saves lives nor protects the environment. Why? Because low speed = more TIME on the road = more exhaust and increased chances of accidents.

C basically says that LOW speed = more TIME on the road = more cars on the road.

This does not reveal a FLOW in the reasoning. If anything, C AGREES with the argument.