When exercising the muscles in one’s back, it is important

Question

When exercising the muscles in one’s back, it is important, in order to maintain a healthy back, to exercise the muscles on opposite sides of the spine equally. After all, balanced muscle development is needed to maintain a healthy back, since the muscles on opposite sides of the spine must pull equally in opposing directions to keep the back in proper alignment and protect the spine.

Which one of the following is an assumption required by the argument?

(A) Muscles on opposite sides of the spine that are equally well developed will be enough to keep the back in proper alignment.

(B) Exercising the muscles on opposite sides of the spine unequally tends to lead to unbalanced muscle development.

(C) Provided that one exercises the muscles on opposite sides of the spine equally, one will have a generally healthy back.

(D) If the muscles on opposite sides of the spine are exercised unequally, one’s back will be irreparably damaged.

(E) One should exercise daily to ensure that the muscles on opposite sides of the spine keep the back in proper alignment.

Source: LSAT

GMATNinja · Accepted Answer

Thanks  Mahmud6  for the reply!

Let's look at the passage in terms of necessary and sufficient conditions. We are told that "balanced muscle development  is needed  to maintain a healthy back". Does that mean that balanced muscle development is SUFFICIENT to maintain a healthy back? Maybe not. Consider the following example:

A great GMAT score is needed to get accepted to LBS.

So if you get a great GMAT score, will you get accepted to LBS? Maybe, maybe not. Getting a great GMAT score is a NECESSARY condition, but it is not sufficient. You might need a great GMAT score, an outstanding essay, solid referrals, impressive work experience, etc. Similarly, having balanced muscle development is NECESSARY to maintaining a healthy back, but it might not be sufficient. You might need balanced muscle development, lots of flexibility, great posture, healthy vertebrae, etc.

Now take a look at choice (C):

Just because you exercise the muscles on opposite sides equally, does not necessarily mean you'll have balanced muscle development. And even if you have balanced muscle development, you might have an unhealthy back for other reasons.

The passage describes a NECESSARY condition, but choice (C) turns it into a (generally) SUFFICIENT condition. 100 people might have balanced muscle development, but half of them (or more) might have unhealthy backs for other reasons. This doesn't change the fact that having balanced muscle development is a NECESSARY condition. Thus, choice (C) is not a required assumption.

I hope that helps!

Squib17 · Answer

Premise: When exercising the muscles in one’s back, it is important, in order to maintain a healthy back, to exercise the muscles on opposite sides of the spine equally. 
Conclusion:  balanced muscle development is needed to maintain a healthy back  
Premise: since the muscles on opposite sides of the spine must pull equally in opposing directions to keep the back in proper alignment and protect the spine.

Which one of the following is an assumption required by the argument?

(A) Muscles on opposite sides of the spine that are equally well developed will be enough to keep the back in proper alignment.  I had marked this as the answer, but I guess I am wrong. Was confused between A and B]. in the premise it is mentioned we need a balanced muscle development, but option A uses the phrase " equally well developed" which I do not think is the same. 
If I try to negate it and say that it will not be enough to keep the back in proper alignement, it weakens the argument. Will be happy if someone can shed more light on my analysis.]

(B) Exercising the muscles on opposite sides of the spine unequally tends to lead to unbalanced muscle development.  If we negate this, we can easily say that this has to be the answer, because if exercising the muscles unequally does not tend to lead to unbalanced muscle development, then it would shatter the argument! Hence this has to be the answer. ]

(C) Provided that one exercises the muscles on opposite sides of the spine equally, one will have a generally healthy back. this is already mentioned, so this can't be an assumption! ]

(D) If the muscles on opposite sides of the spine are exercised unequally, one’s back will be irreparably damaged.  Out of Scope - No mention of irreparably damaged

(E) One should exercise daily to ensure that the muscles on opposite sides of the spine keep the back in proper alignment. Nothing is mentioned about daily exercise - out of scope. ]

So, looks like the answer should be B. But someone please highlight where is the mistake in my thought process in A.

Regards,
Squib

souvonik2k · Answer

The assumption is C - Provided that one exercises the muscles on opposite sides of the spine equally, one will have a generally healthy back.
Negating this, will break the argument.

jinxd123 · Answer

When exercising the muscles in one’s back, it is important, in order to maintain a healthy back, to exercise the muscles on opposite sides of the spine equally. After all, balanced muscle development is needed to maintain a healthy back, since the muscles on opposite sides of the spine must pull equally in opposing directions to keep the back in proper alignment and protect the spine.

Which one of the following is an assumption required by the argument?

(A) Muscles on opposite sides of the spine that are equally well developed will be enough to keep the back in proper alignment.

(B) Exercising the muscles on opposite sides of the spine unequally tends to lead to unbalanced muscle development.

(C) Provided that one exercises the muscles on opposite sides of the spine equally, one will have a generally healthy back.

(D) If the muscles on opposite sides of the spine are exercised unequally, one’s back will be irreparably damaged.

(E) One should exercise daily to ensure that the muscles on opposite sides of the spine keep the back in proper alignment.

Using POE....

(A) Muscles on opposite sides of the spine that are equally well developed will be enough to keep the back in proper alignment.---Incorrect--- The passage does not state anything like this..(too extreme)

(B) Exercising the muscles on opposite sides of the spine unequally tends to lead to unbalanced muscle development.---Incorrect---Author does not talk about unbalanced muscle development, he rather talks about balanced muscle development..(out of scope)

(C) Provided that one exercises the muscles on opposite sides of the spine equally, one will have a generally healthy back.---Correct--If this is not true the argument falls apart.

(D) If the muscles on opposite sides of the spine are exercised unequally, one’s back will be irreparably damaged.---Incorrect---The passage does not state anything like this..(too extreme)

(E) One should exercise daily to ensure that the muscles on opposite sides of the spine keep the back in proper alignment.---Incorrect---The passage does not state anything like this..(generalization)

---

Thanks in advance for the Kudos I will recieve!!

Octobre · Answer

Ans B?
It starts with equal exercise then subtly switches to balanced development

GMATNinjaTwo · Answer

The OA is B.

To post additional questions not already addressed in this thread, feel free to use the  request verbal experts' reply  button.

KB04 · Answer

When exercising the muscles in one’s back, it is important, in order to maintain a healthy back, to exercise the muscles on opposite sides of the spine equally. After all, balanced muscle development is needed to maintain a healthy back, since the muscles on opposite sides of the spine must pull equally in opposing directions to keep the back in proper alignment and protect the spine.

Which one of the following is an assumption required by the argument?

(A) Muscles on opposite sides of the spine that are equally well developed will be enough to keep the back in proper alignment.

(B) Exercising the muscles on opposite sides of the spine unequally tends to lead to unbalanced muscle development.

(C) Provided that one exercises the muscles on opposite sides of the spine equally, one will have a generally healthy back.

(D) If the muscles on opposite sides of the spine are exercised unequally, one’s back will be irreparably damaged.

(E) One should exercise daily to ensure that the muscles on opposite sides of the spine keep the back in proper alignment.

Using POE....

(A) Muscles on opposite sides of the spine that are equally well developed will be enough to keep the back in proper alignment.---Incorrect--- The passage does not state anything like this..(too extreme)

(B) Exercising the muscles on opposite sides of the spine unequally tends to lead to unbalanced muscle development.---Incorrect---Author does not talk about unbalanced muscle development, he rather talks about balanced muscle development..(out of scope)

(C) Provided that one exercises the muscles on opposite sides of the spine equally, one will have a generally healthy back.---Correct--If this is not true the argument falls apart.

(D) If the muscles on opposite sides of the spine are exercised unequally, one’s back will be irreparably damaged.---Incorrect---The passage does not state anything like this..(too extreme)

(E) One should exercise daily to ensure that the muscles on opposite sides of the spine keep the back in proper alignment.---Incorrect---The passage does not state anything like this..(generalization)

---

Thanks in advance for the Kudos I will recieve!!

JS1290 · Answer

Can anyone please explain to me why option C is incorrect? When I negated the to option, it seemed to weaken the conclusion.

KB04 · Answer

Can anyone please explain to me why option C is incorrect? When I negated the to option, it seemed to weaken the conclusion. I am happy to help

The problem with this statement is the word "generally". This means that sometimes one will have a healthy back and sometimes one will not have a healthy back. This is not necessary for the argument to hold. Also, if you negate the option "Provided that one exercises the muscles on opposite sides of the spine equally, one will NOT have a GENERALLY healthy back" which also means that sometimes one will have a healthy back and sometimes one will not have a healthy back and that's how it doesn't do anything to the argument.

testcracker · Answer

I think the word "MUST" in the premise - "since the muscles on opposite sides of the spine MUST pull equally in opposing directions to keep the back in proper alignment and protect the spine." - has made the choice B correct choice

SVP482 · Answer

The main stimulus talks during the exercise, where as the option C talks about the general statement of having a healthy back if one exercise the muscles. In case of Option B, it clearly mentions "during the exercise if done unequally, it will lead to unbalanced muscle development" which on negating will falsify the conclusion.

sunny91 · Answer

Hi,
I was torn between B and C. C looks more like an inference or conclusion to me. but, on a second thought C can be an assumption, that falls under If X then Y.

(C) Provided that one exercises the muscles on opposite sides of the spine equally, one will have a generally healthy back.

If one exercises the muscles on opposite sides of the spine equally, then one will have a generally healthy back.
If we negate this, if one exercises the muscles on opposite sides of the spine equally, then one will not have a generally healthy back. The argument falls. Please help me to understand how to eliminate C.

Mahmud6 · Answer

B. Exercising the muscles on opposite sides of the spine  un equally tends to lead to  un balanced muscle development.

Since we have two negative words we can paraphrase the sentence as below;
Exercising the muscles on opposite sides of the spine  equally  tends to lead to  balanced  muscle development.

So, by negating we get, 
Exercising the muscles on opposite sides of the spine  DOES NOT   equally  tends to lead to  balanced  muscle development.

This breaks down the conclusion, thereby, it is a correct assumption.

sunny91 · Answer

Hi Mahmud6,
Yes option B by negating, we can see the conclusion breaks. Can you kindly mention how C is incorrect. Even by negating C, the conclusion breaks.

Mahmud6 · Answer

Hi  sunny91 ,

Though I am still learning, I will try to present my reasoning.

The word 'generally' means 'in most cases' or 'usually'. So, to paraphrase the choice C, it stands-

'provided that one exercises the muscles on opposite sides of the spine equally, one will have a healthy back  in most cases '

So, by negating we get,

'provided that one exercises the muscles on opposite sides of the spine equally, one will  NOT  have a healthy back  in most cases  ---> which indicates that if one exercises the muscles on opposite sides of the spine equally,  in some cases one will have a healthy back.

I hope this doesn't break down the conclusion.

manishtank1988 · Answer

Good Afternoon Everyone 
Special thanks to  GMATNinja ,  KB04  and Hasan for their help and explanation. I only have 1 more question - 
How do we realize when to use necessary and sufficient point of reference and when to use simple negation. I hope my questions makes sense, because when seen as explained by GMATNINJA it makes sense but how to when to think on those lines, especially in exam when we all would only have few seconds?

So are there any markers we can look out for while reading CR for this kind of question?
Please explain.
Thanks

GMATNinja · Answer

I'm glad that you're enjoying our explanations,  manishtank1988 ! Sadly, there is no formula or algorithm for navigating these questions. As described in our  CR Guide for Beginners , you have to read carefully and think really hard about what's important in each unique passage.

When you see the words "is needed" in the phrase "balanced muscle development   is needed   to maintain a healthy back," you should be thinking, "okay, 'is needed'... this must be a  necessary  condition, not a sufficient one." There's no way around that part. If you are looking for cues/markers, trying too hard to group a passage with something you've seen in the past, and then trying to tackle it using an overly formulaic approach, you'll likely gloss over key details, fall for trap answers, and/or misinterpret something.

Sorry for the not-so-satisfying response, but I hope that helps a little bit!

manishtank1988 · Answer

Understood GMATNinja , thanks for the explanation...

DharLog · Answer

I noticed in assumption questions, that very frequently the options are or the repetition of an argument (it will be wrong every time), or generalizations (will be wrong every time), or too extreme (similar to previous one - wrong every time)
or the missing part of puzzle (very often) or something like negation of negation (do not know how to tell it in a right way - here it is option B - the right one)

When exercising the muscles in one’s back, it is important

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When exercising the muscles in one’s back, it is important

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