Find all School-related info fast with the new School-Specific MBA Forum

It is currently 25 Oct 2014, 18:05

Close

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
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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

PS-prep

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Director
Director
User avatar
Joined: 03 Sep 2006
Posts: 889
Followers: 6

Kudos [?]: 171 [0], given: 33

PS-prep [#permalink] New post 23 Jun 2007, 23:40
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Pl. exp.
Attachments

untitled.PNG
untitled.PNG [ 68.39 KiB | Viewed 183 times ]

CIO
CIO
User avatar
Joined: 09 Mar 2003
Posts: 466
Followers: 1

Kudos [?]: 29 [0], given: 0

 [#permalink] New post 24 Jun 2007, 14:55
First step, clear the root out of the bottom. You do that by multiplying the fraction by 1, using the root on the bottom over itself:

1/root(x+y) * root(x+y)/root(x+y) =

root(x+y)/(x+y)

Now you've got something to compare to.

The first one can't be right, because we don't know anything about xy, and the numerator is the same. If x and y are both 1, then x + y will be more than xy, if they're both 20, then the opposite is true.

The second one does seem to be right. I've tried a bunch of numbers, and it looks like root(x+y) is always less than root(x) + root(y).

The third one can't be right, because subtracting those two roots will be smaller than adding them, even inside the radical.

So two only.
  [#permalink] 24 Jun 2007, 14:55
    Similar topics Author Replies Last post
Similar
Topics:
PS-Prep, time killer misterJJ2u 6 28 Jun 2007, 08:19
PS-prep LM 1 23 Jun 2007, 23:46
PS-prep LM 3 23 Jun 2007, 23:45
Display posts from previous: Sort by

PS-prep

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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®.