Critical Reasoning

Hello experts:

I would like to further this CR discussion,as I still have some doubt on it.

According to the principle of assumption,negate the option then it will weaken the conclusion.

First,the conclusion is inmates whos had taken such courses committed far fewer crimes overall than other inmates.

Now let's see option A:

A. Not being able to take college-level courses while in prison is unlikely to deter anyone from a crime that he or she might otherwise have committed.

negative 1: Being able to take college-level courses while in prison is unlikely to deter anyone from a crime that he or she might otherwise have committed.(Weaken)
negative 2:Not being able to take college-level courses while in prison is likely to deter anyone from a crime that he or she might otherwise have committed.(Weaken)

C. The group of inmates who chose to take college-level courses were not already less likely than other inmates to commit crimes after being released.

negative 1:The group of inmates who chose to take college-level courses were not already likely than other inmates to commit crimes after being released.(Strengthen)
negative 2:The group of inmates who chose to take college-level courses were already less likely than other inmates to commit crimes after being released.(Strengthen)

Why not choose A?

Thank you!

Testluv wrote:received a pm.

A when negated destroys the argument!!

Yes, it certainly does. Choice A is indeed a necessary assumption. Choice A reads:

A. Not being able to take college-level courses while in prison is unlikely to deter anyone from a crime that he or she might otherwise have committed.

which, removing the double negatives "not" and "unlikely" can be read as:

"Being able to take college-level courses while in prison IS likely to deter anyone from a crime that he or she might otherwise have committed."

which, if we negate, becomes:

"Being able to take college-level courses while in prison ISN'T likely to deter anyone from a crime that he or she might otherwise have committed."

in which case the argument certainly falls apart.

___________

does C mean

both groups were equally probable
OR

presence of already here does the trick ?

Not sure I quite understand your question but Ron was bang on when he said that the word "already" in choice C also makes choice C a necessary assumption. "already" means before actually taking the courses.

Choice C when negated also destroys the assumption: If the group of inmates who chose to take college-level courses WERE already less likely than other inmates to commit crimes after being released, then the argument falls apart for the reasons Ron discussed above.

There are two logically correct answer choices here, two necessary assumptions among the answer choices: choices A and C.

This is a bad question, and I wonder what the source is.

Hello Testluv,

In order to negate the double negetive statements such as the one above, do we need to remove both the negetives?

Let us take a simple sentence as follows:
If Sam does not wear the red uniform, he is unlikely to get entry into the school premises.

Would the negetive of this statement be:
If Sam wears the red uniform, he is likely to get entry into the school premises?

I would doubt this. I think we may have to remove only one of the two negatives in order to derive the negation statement.

And so I feel that the question is correctly written. Could you please provide your thoughts?

Thanks.

Hi,

what you rewrote isn't a negation of the original statement; instead it is a rephrase. When we have a double negative and remove both negatives, we arrive at a rephrase of the original (which is usually more clear because there aren't any negatives).

The negation of the original statement would be:

If Sam does not wear the red uniform, he IS LIKELY to get entry into the school premises.

Testluv wrote:Hi,

what you rewrote isn't a negation of the original statement; instead it is a rephrase. When we have a double negative and remove both negatives, we arrive at a rephrase of the original (which is usually more clear because there aren't any negatives).

The negation of the original statement would be:

If Sam does not wear the red uniform, he IS LIKELY to get entry into the school premises.

Thanks Testluv. I have some follow-up questions.

1. If we want to negate such statements, how do we decide in such cases which of the two negations should be removed ?

2. If we remove both the negations, would the resulting statement be a valid rephrase.

For example, if we remove both the negations in the above example, the sentence reads:
"If Sam wears the red uniform, he is likey to get entry into the school premises".

But what if wearing a red uniform is a necessary but not a sufficient condition for an entry into the school premises? Can the statement above be still a valid rephrase?

Ron, TEstluve, member, pls, discuss more.

This is GMATPREP question. GMATPREP is the only official source of HARD QUESTIONS. and I do not think this is bad.

My idea is that

Evidence: taking course shows crime decline

conclusion: not taking the course does not create crime decline.

Assumption: course causes crime decline, or, the persons taking the course do not show crime decline before taking the courses. C is correct

A IS CONCLUSION, NOT ASSUMPTION.

Is my thinking correct?, A is conclusion which we need prove.

lunarpower wrote: If you're going to argue that X causes Y, one necessary precondition (assumption) is that Y DOESN'T cause X.
this is precisely what is asserted in (c), which should be the correct answer.

Ron Sir, Can you elucidate/elaborate more on this logic on Option C. Thanks!

This problem has really got into my nerves can anybody please explain me how negation test is working on this problem?

Anaira Mitch wrote:This problem has really got into my nerves can anybody please explain me how negation test is working on this problem?

Hi there,

This is a causality problem.

X causes Y

We can prove that this is not a causal argument. If we can do any of these two =

1. Y also causes X than in that case the causality is broken.
2. X also causes something else say Z.

In our question the causal argument established in the question is =

Prisoners who take college-level courses in prison commit far fewer crimes after release than those who do not take college level courses. So the causality is that college-level courses taken by criminals lead to fewer crimes.

Option C breaks the causality =
C. The group of inmates who chose to take college-level courses were not already less likely than other inmates to commit crimes after being released.

It clearly states that there are many criminals who even if do not take the college level course are less probable to commit crime after release.
This option breaks the causality established. Did you get this?

richachampion wrote:

Anaira Mitch wrote:This problem has really got into my nerves can anybody please explain me how negation test is working on this problem?

Hi there,

This is a causality problem.

X causes Y

We can prove that this is not a causal argument. If we can do any of these two =

1. Y also causes X than in that case the causality is broken.
2. X also causes something else say Z.

In our question the causal argument established in the question is =

Prisoners who take college-level courses in prison commit far fewer crimes after release than those who do not take college level courses. So the causality is that college-level courses taken by criminals lead to fewer crimes.

Option C breaks the causality =
C. The group of inmates who chose to take college-level courses were not already less likely than other inmates to commit crimes after being released.

It clearly states that there are many criminals who even if do not take the college level course are less probable to commit crime after release.
This option breaks the causality established. Did you get this?

Hello Richa,

Thank You for your inputs. Now it's clear to me.