Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 350,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

A) n < 8
Not a must, because n still can be 8, 9 or 10
B) n = -6
Not a must, because n still can be -5 till 10
D) -10 < n < 7
Not a must because n still can be 7, 8, 9 or 10

C) n > -8
Yes it must be greater than -8, but we still have -7 which is not valid for n.

It's questions like these that make one wonder what is this exam really testing. I'll bet the answer if C because the question doesn't ask if the answer choice will fall within the established perameters. It only asks which must be true and all numbers in that set will be greater than -8. It stinks but I think the answer is C.

Please help advice how to attack the attached question:

n can be -6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10 Looking at answer choices 1: n<8, False as n can be any value less than -6 2: n = -6 True as possible value 3: n>-8, False as n can be -7 which is incorrect 4: -10<n<7, False as n can be -9, -8,-7 which is incorrect 5: Not possible as (2) is correct.

The OA marked is impossible with the question given. What is the source of question?

However, IMO, since the question is mentioning " which of the following must be true", we can eliminate answer choice (2), to leave (5) as the only correct option.

If it is true that -6 =< n =<10, which of the following must be true?

A. n < 8 B. n = -6 C. n > -8 D. -10 < n < 7 E. None of the above

The stem says that \(-6\leq{n}\leq{10}\). This info is given to be true. The question asks which of the following MUST be true?

A. \(n<8\) --> n can be 9, hence this might be wrong. B. \(n=-6\) --> we don't know the exact value of n, we just know that n is in the range \(-6\leq{n}\leq{10}\). Hence this might be wrong. C. \(n>-8\) --> ANY value of n from the range \(-6\leq{n}\leq{10}\) is more than -8, hence this info is ALWAYS true. Correct answer. D. \(-10<n<7\) --> n can be 8, hence this might be wrong. E. None.

Thanks for correcting on this one. It appears that interpreting the question is more than half the battle won. In the answer choice (C), there is a tendency in this one to take a value of -7 & mark this choice as incorrect. However, if you look at the larger set of -6=<n=<10, then all the values of n here are greater than -8.

If you tell me that you took the GMAT 3 times and each time you scored between 710 and 770, and I say "Wow! you scored above 700 each time", will my statement always be true?

Re: Problem solving - inequality - 700 level [#permalink]
04 Aug 2011, 04:06

Expert's post

shashankp27 wrote:

bschool83 wrote:

agdimple333 and zuberahmed,

What if n = -5, 0, or 5? Then answer choice B (n = –6) will fall apart.

–6 <= n <= 10 means all values between and equal to -6 and 10.

Answer choice C, n > –8 holds true for all available values of n. Hence answer is C.

how does it 'fall apart' ? could you please elaborate...

Focus on the question's wording: If it is true that –6 <= n <= 10, which of the following [highlight]must be true[/highlight]?

'must be true' implies that no matter what value n takes (out of the given range), 'which of the following will definitely hold?' We have to find that option that will remain true. It is different from 'which of the following CAN be true?' i.e. which of the following is possible... Given -6 <= n <= 10

n = -6 is possible. But it will not hold for all possible values of n i.e. if n = 5, then n is not equal to -6. So 'n = -6' is not a 'must be true' condition.

On the other hand, n > -8 will always be true. If n = -6, then n > -8 If n = 0, then n > -8 If n = 4, then n > -8 If n = 10, then n > -8 Hope you got the point. No matter which value n takes out of the available values, n > -8 will always be true. For every value of n, n will be more than -8. Therefore, answer will be C.

GMAT loves to lay this trap. Be very careful. Make sure you understand exactly what the question is asking. _________________

Re: Problem solving - inequality - 700 level [#permalink]
05 Aug 2011, 19:16

bschool83 wrote:

If it is true that –6 <= n <= 10, which of the following must be true?

n < 8 n = –6 n > –8 -10 < n < 7 none of the above

There appears to be a very simple way to understand this problem...Popped into my head after seeing the tedious ways of making all understand, so thought of posting it.

Whenever you see a MUST BE TRUE question of the form IF [X], then [Y] MUST BE TRUE Visualize/draw as a VENN DIAGRAM the above two conditions X and Y....In this case :

Fact : –6 <= n <= 10 ------- (X)

All the Other Choice -------- (Y)

When will this be a MUST BE TRUE ?

When X is always contained inside Y/ Y is equal to or a superset of Y

Now, you have got this idea....Just plug in the choices for Y putting X constant.

n < 8 fails for n < -6 and –6 <= n <= 10 n = –6 fails for all values when n <> -6 and –6 <= n <= 10 n > –8 does not fail for any value when n > –8 and –6 <= n <= 10 -10 < n < 7 fails for all values when n = -9,-8,-7 and and –6 <= n <= 10 none of the above

How the growth of emerging markets will strain global finance : Emerging economies need access to capital (i.e., finance) in order to fund the projects necessary for...

One question I get a lot from prospective students is what to do in the summer before the MBA program. Like a lot of folks from non traditional backgrounds...