m0515 : Quant Question Archive [LOCKED]
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 08 Dec 2016, 05:24

### GMAT Club Daily Prep

#### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# m0515

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
Intern
Joined: 17 Jan 2009
Posts: 2
Followers: 0

Kudos [?]: 0 [0], given: 0

### Show Tags

30 Jan 2009, 06:11
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If x is a positive integer, is sqrt{x} < 2.5x - 5?

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

The answer I chose was E but the correct answer is A -

My rationale -

From Statement 1, we know x can only be 1 or 2, since x is a positive integer. We need to test if the answer is the same for both x . If x=1 , the answer to the question is CANNOT DETERMINE sqrt{1} = +/- 1: sqrt{1} < 2.5*1 - 5 .
For x = 2 : sqrt{2} < 0. The answer is CANNOT DETERMINE. Thus, Statement 1 is insufficient.

Statement 2 does not help much as x can be 2 or 11. The inequality does not hold consistent for both of these values. Insufficient.

Statement 1 and 2 together x = 2

Thanks
CEO
Joined: 17 Nov 2007
Posts: 3589
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 530

Kudos [?]: 3455 [0], given: 360

### Show Tags

30 Jan 2009, 07:57
abdemt wrote:
...the answer to the question is CANNOT DETERMINE sqrt{1} = +/- 1: sqrt{1} < 2.5*1 - 5 ....

$$\sqrt{1}=1$$ not $$\pm1$$

This was discussed in some threads that $$\sqrt{n}$$ represents a positive root and solution of equitation $$x^2=n$$ is $$\pm\sqrt{n}$$, where $$\sqrt{n}$$ is a positive number
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Intern
Joined: 17 Jan 2009
Posts: 2
Followers: 0

Kudos [?]: 0 [0], given: 0

### Show Tags

30 Jan 2009, 08:09
Thank you - that clears my doubt

Regards
SVP
Joined: 29 Aug 2007
Posts: 2492
Followers: 67

Kudos [?]: 728 [0], given: 19

### Show Tags

30 Jan 2009, 13:27
abdemt wrote:
If x is a positive integer, is $$sqrt{x}$$ < (2.5x - 5)?

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

The answer I chose was E but the correct answer is A - Thanks

59-p564448?t=75172#p564448
_________________

Gmat: http://gmatclub.com/forum/everything-you-need-to-prepare-for-the-gmat-revised-77983.html

GT

Re: m0515   [#permalink] 30 Jan 2009, 13:27
Display posts from previous: Sort by

# m0515

 post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.