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:

Re: Gmatclub test M 05, question 15/37 [#permalink]

Show Tags

14 Mar 2010, 21:01

1

This post received KUDOS

BarneyStinson wrote:

If x is a positive integer, is sqrt(x) < 2.5*x - 5 ?

1) x < 3 2) x is a prime number

st 1) x< 3 ==> x can be 1 or 2 x = 1 --> -2.5 > 1 .. NO x = 2 --> 0>1.414 .. NO sufficient st 2 ) x is prime .. x = 2, NO x=3 or above YES not sufficient

A

BarneyStinson wrote:

X is positive integer, sqrt(x) can still be negative.

the square roots of x are +sqrt(x) and -sqrt(x) sqrt(x) is ALWAYS POSITIVE

X is positive integer, sqrt(x) can still be negative.

1: if x>0 and x<3 then possible values 1,2 (0 is neither positive nor negative) with both values sqrt(x) < 2.5*x - 5. hence sufficient. 2: x can be 2,3,5,7,11 ..... any value of x greater than 4 will result in sqrt(x) > 2.5*x - 5 hence insufficient. Hence A.

Also sqrt of positive number is always +ve it can't be negative.

Re: Gmatclub test M 05, question 15/37 [#permalink]

Show Tags

14 Mar 2010, 23:35

1

This post received KUDOS

sidhu4u wrote:

bangalorian2000 wrote:

Also sqrt of positive number is always +ve it can't be negative.

Sqrt of any positive number can be negative, its not necessarily to be positive. for example, if we have 9 as number, than its sqrt can be 3 or -3 since 9 = 3*3 or (-3)*(-3)

Mate just need to clarify that on Gmat Land , root of any number is +ve

i.e. root of 4 has to be taken as 2 only and not -2....

however if you are given x^2 = 4 then that would give x = +2 and -2

Re: Gmatclub test M 05, question 15/37 [#permalink]

Show Tags

14 Mar 2010, 22:52

bangalorian2000 wrote:

Also sqrt of positive number is always +ve it can't be negative.

Sqrt of any positive number can be negative, its not necessarily to be positive. for example, if we have 9 as number, than its sqrt can be 3 or -3 since 9 = 3*3 or (-3)*(-3)
_________________

It’s quickly approaching two years since I last wrote anything on this blog. A lot has happened since then. When I last posted, I had just gotten back from...

Since my last post, I’ve got the interview decisions for the other two business schools I applied to: Denied by Wharton and Invited to Interview with Stanford. It all...

Marketing is one of those functions, that if done successfully, requires a little bit of everything. In other words, it is highly cross-functional and requires a lot of different...