Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 28 May 2017, 01:01

### 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

# Square Roots DS Question from Kaplan...

Author Message
Intern
Joined: 05 Jan 2006
Posts: 15
Location: Indianapolis
Followers: 0

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

Square Roots DS Question from Kaplan... [#permalink]

### Show Tags

23 Jan 2006, 17:59
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

This question is from Kaplan:

If x is a positive number, is x less than 1 ?

1) x > sqrt(x)
2) -sqrt(x) > -x

My thought process was :

considering statement 2, multiply both sides by negative 1. It gives the same statement as 1.

Now with statement 1, if x = 4, x > 2 which is x > sqrt(4) => x>1
if x = 1/4, then x > -1/2 which is x >sqrt(1\4) => x<1.

So my answer was both of the statements put together are insufficient.

But Kaplan's reasoning was there can't be any number x which is less than 1 and satisfies the condition x > sqrt(x). Obviously Kaplan is assuming that x is a positive integer. But the question says "x is a positive number" which means it can be positive fractional number.

Could some one please clarify whether it is a valid assumption by Kaplan ? Am I missing missing something here ?
 Kaplan GMAT Prep Discount Codes Economist GMAT Tutor Discount Codes Magoosh Discount Codes
VP
Joined: 20 Sep 2005
Posts: 1018
Followers: 3

Kudos [?]: 36 [0], given: 0

### Show Tags

23 Jan 2006, 18:35
x = 1/4

Statement 1 can't be true since 1/4 is not greater than 1/2.

Statement 2 can't be true since -1/2 is not greater than -1/4.

Intern
Joined: 05 Jan 2006
Posts: 15
Location: Indianapolis
Followers: 0

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

### Show Tags

23 Jan 2006, 18:51
[quote="lhotseface"]x = 1/4

Statement 1 can't be true since 1/4 is not greater than 1/2.

Statement 2 can't be true since -1/2 is not greater than -1/4.

But why should we consider only the positive square root (1/2 ?). The problem statement says x is positive it doesn't talk about the positive square root. So in that case 1/4 > -1/2 . And as you have shown 1/4 can't be greater than 1/2 (the other square root). So my little brain says answer should be E. Please correct me if I am wrong
SVP
Joined: 16 Oct 2003
Posts: 1805
Followers: 5

Kudos [?]: 154 [0], given: 0

### Show Tags

23 Jan 2006, 19:21
Choose numbers

From 1) if x = 64 then x > sqrt x, where as if x = 0.64 then x < sqrt x Hence sufficient

From 2) -sqrt(x) > -x hence sqrt(x) < x and the argument from 1) follows. This is also sufficient. Answer should be D.
VP
Joined: 20 Sep 2005
Posts: 1018
Followers: 3

Kudos [?]: 36 [0], given: 0

### Show Tags

23 Jan 2006, 19:24
On the GMAT, sqrt(4) = 2 and not (2,-2).

thegmatguy wrote:
lhotseface wrote:
x = 1/4

Statement 1 can't be true since 1/4 is not greater than 1/2.

Statement 2 can't be true since -1/2 is not greater than -1/4.

But why should we consider only the positive square root (1/2 ?). The problem statement says x is positive it doesn't talk about the positive square root. So in that case 1/4 > -1/2 . And as you have shown 1/4 can't be greater than 1/2 (the other square root). So my little brain says answer should be E. Please correct me if I am wrong
Senior Manager
Joined: 11 Jan 2006
Posts: 269
Location: Chennai,India
Followers: 1

Kudos [?]: 4 [0], given: 0

### Show Tags

23 Jan 2006, 22:48
it is D , got i tried taking x = 0.4 and sqrt(0.4)
_________________

vazlkaiye porkalam vazltuthan parkanum.... porkalam maralam porkalthan maruma

Director
Joined: 04 Oct 2005
Posts: 583
Location: Chicago
Followers: 1

Kudos [?]: 7 [0], given: 0

### Show Tags

23 Jan 2006, 23:15
D for me..
a)x=4 => 4>2 so xis not less than 1..This stmt wont suffice with fractional values.

b) x=4=> -2>-4..so x is not less than 1...This stmt wont suffice again with fractional values.
23 Jan 2006, 23:15
Display posts from previous: Sort by