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 500,000 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:

1) n^2-1 is an odd integer 2) 3n+4 is an even integer

According to GMAT answer it is D but I disagree and have to say it is E because n can be 0 which is not an even number while satisfying both requirement.

Any thoughts?

Hello Ekin, welcome to the Gmat Club.

First of all I must say that zero IS an even integer, though it's neither positive nor negative.

Even number (even integer) \(n\) is of the form \(n=2k\), where \(k\) is an integer, so for \(k=0\), \(n=2*0=0\).

As for the question:

(1) \(n^2-1=(n-1)(n+1)=odd\) --> both \(n-1\) and \(n+1\) must be odd to produce an odd integer when multiplied, hence \(n\) is be even. Sufficient.

(2) \(3n+4=even\) --> \(3n\) must be even --> \(n\) must even. Sufficient.

1) n^2-1 is an odd integer 2) 3n+4 is an even integer

According to GMAT answer it is D but I disagree and have to say it is E because n can be 0 which is not an even number while satisfying both requirement.

If n is an integer, is n even? (1) (n^2) - 1 is an odd integer. (2) 3n + 4 is an even integer.

I personally think it is E, because putting n as 0, both the condition are insufficient. But the OA does not include 0 as one of the conditions to check.

Please explain or am I missing something here?

Thanks, Sandeep Nerli (Taking GMAT on 30th of June, 2010)

Re: OFFICIAL GUIDE 12th Edition DS Q24 [#permalink]

Show Tags

11 Jun 2010, 01:30

IMO A.

Why n=0 is not a valid condition?

sandeepnerli wrote:

If n is an integer, is n even? (1) (n^2) - 1 is an odd integer. (2) 3n + 4 is an even integer.

I personally think it is E, because putting n as 0, both the condition are insufficient. But the OA does not include 0 as one of the conditions to check.

Please explain or am I missing something here?

Thanks, Sandeep Nerli (Taking GMAT on 30th of June, 2010)

_________________

Want to improve your CR: http://gmatclub.com/forum/cr-methods-an-approach-to-find-the-best-answers-93146.html Tricky Quant problems: http://gmatclub.com/forum/50-tricky-questions-92834.html Important Grammer Fundamentals: http://gmatclub.com/forum/key-fundamentals-of-grammer-our-crucial-learnings-on-sc-93659.html

Re: OFFICIAL GUIDE 12th Edition DS Q24 [#permalink]

Show Tags

11 Jun 2010, 01:47

Sorry, I want to change my answer to D.
_________________

Want to improve your CR: http://gmatclub.com/forum/cr-methods-an-approach-to-find-the-best-answers-93146.html Tricky Quant problems: http://gmatclub.com/forum/50-tricky-questions-92834.html Important Grammer Fundamentals: http://gmatclub.com/forum/key-fundamentals-of-grammer-our-crucial-learnings-on-sc-93659.html

Re: OFFICIAL GUIDE 12th Edition DS Q24 [#permalink]

Show Tags

11 Jun 2010, 02:23

IN DS, the two given statement are correct. If you are checking for their correctness then it is wrong.

Here, both statements are true and you need to consider that for which values these 2 statements meeting the criteria.

Let me know if you have some questions.

innersanctum wrote:

if n=3( an integer) n^2-1=3^2-1=8 is not odd integer 3n+4=3*3+4=13 is not even integer.

Both these conditions are insufficient.

_________________

Want to improve your CR: http://gmatclub.com/forum/cr-methods-an-approach-to-find-the-best-answers-93146.html Tricky Quant problems: http://gmatclub.com/forum/50-tricky-questions-92834.html Important Grammer Fundamentals: http://gmatclub.com/forum/key-fundamentals-of-grammer-our-crucial-learnings-on-sc-93659.html

Re: OFFICIAL GUIDE 12th Edition DS Q24 [#permalink]

Show Tags

11 Jun 2010, 02:29

Hi,

The question clearly states that n is an integer, so n can be 0 and I agree that for n= 0 both the statements hold true, but since 0 is neither negative nor positive, I think the answer should be E, not D

After days of waiting, sharing the tension with other applicants in forums, coming up with different theories about invites patterns, and, overall, refreshing my inbox every five minutes to...

I was totally freaking out. Apparently, most of the HBS invites were already sent and I didn’t get one. However, there are still some to come out on...

In early 2012, when I was working as a biomedical researcher at the National Institutes of Health , I decided that I wanted to get an MBA and make the...