In an experiment, some volunteers were assigned to take aerobics class

Question

In an experiment, some volunteers were assigned to take aerobics classes and some others to take weight - training classes. After three months, each performed arduous mathematical calculation. just after the challenge, the measurable stress symptoms of volunteers in the aerobics classes were less than those of the volunteers in weight training classes . This provides good evidence that aerobics exercise helps the body handle psychological stress.

Which of the following is an assumption the argument requires?

(A) Three months is enough time for the body to fully benefit from aerobic exercise.

(B) The volunteers who were assigned to the aerobics classes did not also lift weights outside the classes.

(C) On average , the volunteers who were assighed to the aerobic s classes got more exercise in the months in which they took those classes than they had been gettinh before beginning the experiment.

(D) On average, the volunteers assigned to the aerobics classes found it less difficult to perform the mathematical calculation than did the volunteers assigned to the weight training classes.

(E) On average, the volunteers assigned to the aerobic classes got a greater amount of aerobic exercise overall during the experiment, including any exercise than did volunteers assigned to the weight training classes.

AndrewN · Accepted Answer

Hello,  Shikhar22 . In a question such as this, you want to make sure you do not lose sight of the question stem itself. We are asked about  an assumption the argument  requires   (my  italics ). What is that argument? That    provides good evidence that aerobics exercise helps the body handle psychological stress.  That is, the volunteers who took aerobics classes instead of weight-training classes demonstrated lower  measurable stress symptoms  while performing  arduous mathematical calculation .

Choice (B) is  not  a  required  assumption because, among other things, it gives us a glimpse into one half of the volunteer group only. Who is to say that volunteers who took aerobics classes did not also lift weights? Would an answer to the question such as  Yes, they did, but only a little  or  Some did, while others did not  affect the argument? Consider the weight-lifting group of volunteers as well. Who is to say that these participants could not have enjoyed aerobic activity outside of their weight-lifting classes? We simply do not have information in the passage to lean on to qualify this answer choice as a necessary assumption.

Choice (E) is poorly transcribed, just as the passage itself was. I would like to see the original passage and answer choices. The part after the second comma, from  including  on, is poorly written. Nevertheless, it directly compares the amount of aerobic exercise that volunteers in one group got versus the amount of the same type of exercise from the other group, and the balance tilts in favor of the aerobics-class group. To test a  required  assumption, you can drag and drop the answer choice between the premises and the conclusion. Take a look at (B) and (E) in this manner, and you will see that the latter must be true for the argument to be made.

Premise : The measurable stress symptoms of volunteers in the aerobics classes were less than those of the volunteers in weight training classes.

Assumption  (answer choice (B)): The volunteers who were assigned to the aerobics classes did not also lift weights outside the classes.

Conclusion/Argument :   This provides good evidence that aerobics exercise helps the body handle psychological stress.

Although I would say that (B) bolsters the argument, it is not strictly  required  to bridge the gap from premise to conclusion. Now, try the same with (E):

Premise : The measurable stress symptoms of volunteers in the aerobics classes were less than those of the volunteers in weight training classes.

Assumption  (answer choice (E)): On average, the volunteers assigned to the aerobic classes got a greater amount of aerobic exercise overall during the experiment, including any exercise than did volunteers assigned to the weight training classes.

Conclusion/Argument :   This provides good evidence that aerobics exercise helps the body handle psychological stress.

Sure, the latter part of (E) is garbled—I suspect some words or punctuation may be missing. However, it must be true that for the argument to be made on the basis of the information provided, the group assigned to aerobics classes had to have gotten more  aerobic exercise overall during the experiment —regardless of whether the weight-lifting volunteers also participated in aerobic exercise on their own time—or else the argument could not be put forth as is.

Anyway, that is my take. I hope it is helpful to you and others who may stumble across the thread. Thank you for thinking to ask me.

- Andrew

Kailash331 · Answer

This makes no sense.. nowhere does it mention that doing more in sports helps you to reduce stress and it’s not some sort of assumption that is required

Posted from my mobile device

kadamhari825 · Answer

Hello experts VeritasKarishma, GMATNinja, egmat, chetan2u

Can you please tell me where i am making mistake?
I chose option B as it is clearly removing potential weakener AND got it wrong.
And also in option E " any exercise " CAN BE weight training also, so how it is closing the gap in the argument?

THANKS

Ozzy11100 · Answer

Hi All,

Despite the objections to the OA, it is correct, IMO.

E is the only necessary assumption.

The argument can be boiled down to: "The group that did the aerobics class DID MORE AEROBIC EXERCISE, and did better on the math tests, therefore aerobic exercise helps with math calculations.

It must be assumed that the people who did the aerobics class (AND did better on the calculations) GOT MORE AEROBIC EXERCISE OVERALL. If they didn't ( i.e. if the weight lifting class actually got more aerobic exercise overall ), then the conclusion breaks down.  Because it would be the case that the group that ACTUALLY did the most aerobic exercise performed worse!

The flaw that one had to notice was the illogic of conflating 'group that was assigned to aerobic exercise' with 'group that actually did the most aerobic exercise.'

I hope this helps!

100mitra · Answer

A is eliminated  - gives about time schedule, out of scope 
 C is eliminated  - before experiment workout schedule, if it is, it would be know fact
 D is eliminated  - Mathematical calculation - irrelevant
 B is eliminated  - gives information about outside the premise workout, not during the experiment

Option E,   looks positive, as it gives information during the experiment, and comparison between two groups, it's very close to be assumption, which can be concluded

Posted from my mobile device

RahulHGGmat · Answer

Hi Experts.

Hope you are doing well.

I am unable to make any sense of this argument. I would request you to help me out in understanding this and explain why E is the correct option and option D and option B is incorrect.

Kailash331 · Answer

Good explanation, thank you! Now I understand

Posted from my mobile device

Shikhar22 · Answer

AndrewN help! I understand why E might be the correct answer, but how do i weigh it against B and eliminate it subsequently? Also, i find the later part of the option E rather confusing. Would like your views on it. Thank you in advance!

Posted from my mobile device

Posted from my mobile device

CuriosStud · Answer

Hi  AndrewN  I have been following your responses and they are quite meaningful and insightful. Kudos to you.

I am still confused on this passage as it makes me draw more assumptions than required. Per the excerpt it is concluded that  aerobics exercise helps the body handle psychological stress  because  the measurable stress symptoms of volunteers in the aerobics classes were less than those of the volunteers in weight training classes .

Now why do I have to assume that intensity or duration has any impact on the outcome? It can so well be the case that volunteers in aerobics program were still able to better manage the stress than those in weight training as the aerobic exercises are quite suitable for efficient stress management despite limited duration or types of the exercises.

On the contrary, I can as well assume with option choice B that if volunteers participating in the aerobics also did weight lifting then the chances of these other programs supporting the outcomes are quite plausible.

Help me in my understanding and do let me know if I have made any wrong inferences above?

- Akshay

AndrewN · Answer

Hello, Akshay. Thank you for the kind words. I think the biggest issue I see is that you appear to be applying real-world logic to such questions. Both Critical Reasoning questions and their Logical Reasoning counterparts on the LSAT are designed to follow a linear or straight-arrow logic. The task is not to assume anything, but to be a detective of sorts, a reader with a keen eye who can stick solely to the information provided in the passage, as well as the answer choices, and select which of the five options falls most in line with the passage and question stem. Also, an argument is to be taken at face value, word for word. In this question, that argument is that aerobics (rather than weight lifting) help the body mitigate stress. The goal, in line with the question, is not to debate that contention or find some  possible  justification for it, but to get yourself into the mindset of one who would make such an argument and think about what would have to be true to get there. (Remember that you are bound by what you see on the screen in the answer choices, so let them shoulder the logical burden.)

I believe I have outlined my views on the question well enough in my earlier post. Choice (B) is too definitive. It does not have to be true that any volunteer stuck to one exercise regimen or the other entirely. But to make an argument that aerobics exercise, as opposed to weight training, confers some particular benefit, we need to find some way to justify that the aerobics exercise of one group was somehow better than that of the other, or there would be little to separate the two groups of volunteers. If all of this still does not make sense, then I would suggest, first, to get back to GMAT™ questions, and, then, to focus on less challenging questions until you see what I mean about the  linear  logic of these types of questions. (Trust me, it took me a while to get it myself.)

Thank you for following up.

- Andrew

CuriosStud · Answer

Dear  AndrewN  I get your point now. I tried to solve the GMAT CR's and then LSAT. Now I understand that while GMAT has a subtler reasoning we need to deduce to answer for challenging questions, For LSAT it's purely linear logic as you rightly mentioned. Thank you for that understanding.

Jeemate · Answer

I can't believe I got this right because this isn't an easy-peasy question nor am I very smart in CR but I can explain this.
The top 3 contenders are B, D &  E . Let's find the right one.
Option B: It says apart from the aerobics, the subjects were not lifting weights. This assumption doesn't change anything because lifting weights is athletic not aerobic so even if they did or did not it wouldn't affect the conclusion that aerobics helped the group.
Option D: This is a classic weakener you would find in GMAT questions and I understand why people fell for it. This weakens the conclusion and is the assumption that is definitely not required because it would make the conclusion false.
 Option E : This option states that the aerobic group got more aerobic training overall than the weight training group. I don't like the mention of other exercises in this option because it contradicts to my reasoning for rejecting B but I think this option makes the conclusion happen.

pratishtha1210 · Answer

Hi experts,

i have a doubt regarding option E that for it to be a assumption not word should have been there right?
So that this parameter is taken care if the volunteers assigned to aerobic class did get greater amount of excercise isn't it weakening the coclusion again ??

(E) On average, the volunteers assigned to the aerobic classes  DID not  got a greater amount of aerobic exercise overall during the experiment, including any exercise than did volunteers assigned to the weight training classes.

IMO Ans should be B
please reply.

ExpertsGlobal5 
 GMATNinja 
 KarishmaB 
 CrackverbalGMAT 
 AndrewN

AndrewN · Answer

No,  pratishtha1210 , the answer choice is fine as written, except for what I have pointed out in an earlier post. If anything, your negation ought to reveal that answer choice (E)  is  the required assumption—i.e. without an assumption that more aerobic exercise led to lower levels of stress in the study, the argument that the experiment  provides good evidence that aerobics exercise helps the body handle psychological stress  cannot hold. To sum up the passage,

Aerobics (A) group → less stress than W group on challenge → aerobics helps reduce stress

Weight training (W) group → less  reduction  in stress than A group on challenge →

We might be able to infer that, in line with the argument, weight training may not help reduce stress as much as aerobics does, but such an inference is not what we are after in this particular question.

If you apply the same negation test to answer choice (B) and remove the  not , I fail to see how we could call the statement a necessary assumption:

Now, we seem to be touting the benefits of weightlifting, as though aerobics was not good enough on its own and the supplemental weight training may have provided the observed stress-reducing benefits. We would expect a different argument in such a case, but this one promotes aerobics.

I know you could make the argument that A + W > W in terms of reducing stress, so A must provide the additional benefits. However, we are seeking to remove W from consideration to provide a link that A is really what matters, per the argument, and an inequality such as A > 0 is pretty meaningless.

- Andrew

unraveled · Answer

In an experiment, some volunteers were assigned to take aerobics classes and some others to take weight - training classes. After three months, each performed arduous mathematical calculation. just after the challenge, the measurable stress symptoms of volunteers in the aerobics classes were less than those of the volunteers in weight training classes .  This provides good evidence that aerobics exercise helps the body handle psychological stress.

Which of the following is an assumption the argument requires?

(A) Three months is enough time for the body to fully benefit from aerobic exercise.

(B) The volunteers who were assigned to the aerobics classes did not also lift weights outside the classes.

(C) On average , the volunteers who were assighed to the aerobic s classes got more exercise in the months in which they took those classes than they had been gettinh  before beginning the experiment .

(D) On average, the volunteers assigned to the aerobics classes found it less difficult to perform the mathematical calculation than did the volunteers assigned to the weight training classes.

(E) On average, the volunteers assigned to the aerobic classes got a greater amount of aerobic exercise overall during the experiment, including any exercise than did volunteers assigned to the weight training classes.

How is it possible that aerobics exercise helps the body handle psychological stress?
Is it that weight-training classes leads people to some kind of disadvantage? 
OR
Is it that aerobics exercise actually helps the body? But how.

I fell for D but unconvincingly. But now i realise it is the result of such an assumption not the actual assumption. E, on the other hand, gives a relationship - although i was not convinced - that slightly leads to conclusion.

One thing that i found, kind of, a revelation. If B is not right than something similar in lines must be there but in opposite direction to help conclude in such a way.

Answer E.

KarishmaB · Answer

Some took aerobics and some weight lifting. 
The aerobics group showed less stress after doing some difficult Math.

Conclusion: Aerobics exercise helps the body handle psychological stress.

Based on the study, we are concluding that aerobics helps the body handle psychological stress because people who did aerobics did better than those who did weight lifting. 
What is the assumption here? That those who did weight training did not also do same amount of aerobics or more on their own. Think about what happens if those who did weight training in the experiment also did aerobics at home for those 3 months? Then we cannot say that aerobics helps the body handle psychological stress because everyone did aerobics. Some other factor must have helped people who did aerobics in the experiment.

(E) On average, the volunteers assigned to the aerobic classes got a greater amount of aerobic exercise overall during the experiment, including any exercise than did volunteers assigned to the weight training classes.

This says that volunteers assigned to aerobic classes got more aerobic exercise than others. This is correct. It is our assumption. If others also got the same amount of aerobics as our aerobics volunteers then we cannot say that aerobics helps. Hence this option is necessary for our conclusion to hold.

(A) Three months is enough time for the body to fully benefit from aerobic exercise.

This is not necessary. Even if the body benefits to a limited extent in 3 months, it could improve the performance in tasks involving psychological stress.

(B) The volunteers who were assigned to the aerobics classes did not also lift weights outside the classes.

It doesn't matter whether aerobics volunteers lifted weights or not. Even if aerobics volunteers lifted weights outside the classes, weight lifting would be common among all volunteers. It would not be a distinguishing factor between the two volunteer groups. The two groups will still be different in the sense that one group would have done aerobics and the other would not have done it. So we can still conclude about aerobics helping. Hence, we don't need this option to be true for our conclusion to hold. 
What is relevant is whether the weight lifters did aerobics on the side. We are concluding about the impact of aerobics. Only if one group does aerobics and the other does not do aerobics can we compare the two and say that aerobics had an impact.

(C) On average , the volunteers who were assighed to the aerobic s classes got more exercise in the months in which they took those classes than they had been gettinh before beginning the experiment.

Who got how much "total exercise" is irrelevant.

(D) On average, the volunteers assigned to the aerobics classes found it less difficult to perform the mathematical calculation than did the volunteers assigned to the weight training classes.

The argument does not discuss the "difficulty" parameter. We do not know how it is related to "stress".

Answer (E)

VIGHNESHKAMATH · Answer

In my first run of the options , I eliminated all of them , but in second run, I was able to confidently eliminate first four options, thus arriving at Option E finally.

My reasoning is as follows: (Remember: Assumption should be ''Must be true'', if is is not so, argument will fail)

Option A: What if handling of stress is just a partial benefit? Argument doesn't fail in that case , so eliminate.

Option B: What if they also lifted the weights, it still proves that aerobics help reduce the stress. Lifting weights is something extra that they would do.

Option C: It is out of scope; I need some comparison between aerobics and weightlifting. This Option only compares scenario of aerobics now and earlier.

Option D: This is a trap, so much relates to our real-world scenario. But remember even if the exams were difficult, a monk may still not take a stress. So, it doesn't help.

Option E: Now comes the importance of identifying the key word of the stem: measurable stress. What if there were other exercises that aerobics practitioners were doing which were not measurable, which may have accounted for this reduced stress. In such a scenario, aerobics then is not the real cause of reduced stress, but some other immeasurable exercise which they might have been doing, so in that case argument conclusion would fail. Option E nicely eliminates this possibility and thus proves to be an ASSUMPTION.

Hope you find my explanation convincing.

Regards
Vighnesh Kamath

Budhaditya_Saha · Answer

But someone please explain, where is it mentioned that aerobic exercise is what reduces stress? I mean weight lifting might also reduce stress and boost brainwork. Why and how are we assuming that mote aerobic exercise = lower stress ?

In an experiment, some volunteers were assigned to take aerobics class

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

In an experiment, some volunteers were assigned to take aerobics class

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards