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

It is currently 28 Aug 2015, 02:11
GMAT Club Tests

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

Crazy Roots

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
CIO
CIO
User avatar
Joined: 09 Mar 2003
Posts: 463
Followers: 2

Kudos [?]: 35 [0], given: 0

Crazy Roots [#permalink] New post 05 Jul 2007, 04:45
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Image
Kaplan Promo CodeKnewton GMAT Discount CodesGMAT Pill GMAT Discount Codes
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jul 2004
Posts: 5067
Location: Singapore
Followers: 24

Kudos [?]: 212 [0], given: 0

 [#permalink] New post 05 Jul 2007, 05:13
(3(135^1/2) + 9/(4+15^1/2))^1/2

(9(15^2) + 9(4-15^1/2))^1/2
(36)^1/2
6
Director
Director
avatar
Joined: 15 Jun 2007
Posts: 504
Followers: 1

Kudos [?]: 9 [0], given: 0

 [#permalink] New post 05 Jul 2007, 05:46
I can simplify
(3(135^(1/2)) + (9/(4+5^(1/2))))^(1/2) to
(3*9(15^(1/2)) + (9/(4+5^(1/2)))^(1/2)

but how do you come up with

(9(15^2) + 9(4-15^1/2))^1/2) ?
Director
Director
User avatar
Joined: 16 May 2007
Posts: 549
Followers: 2

Kudos [?]: 27 [0], given: 0

 [#permalink] New post 05 Jul 2007, 06:13
9/4+sqrt15 can be written as (9/4+sqrt15)(4-sqrt15/4-sqrt15)) = 36-9sqrt15
3sqrt135 = 3sqrt(9*15)= 9sqrt(15)

therefore the given question leads to sqrt(9sqrt15+36-9sqrt15) = 6

Answer is 6
Senior Manager
Senior Manager
avatar
Joined: 04 Jun 2007
Posts: 374
Followers: 1

Kudos [?]: 26 [0], given: 0

 [#permalink] New post 05 Jul 2007, 06:49
=sqrt ( 3 sqrt (15 x 9) + 9/4 + sqrt15)
= sqrt (((9 sqrt15) x (4 + sqrt15) +9)/ 4+ sqrt15)
= sqrt (( 36 sqrt15 +135+ 9)/ 4 + sqrt15)
= sqrt (36 sqrt15 + 144/ 4 + sqrt15)
= sqrt (36 (4 + sqrt15)/ 4 + sqrt15)
= sqrt 36
= 6
Hence, B.
Director
Director
avatar
Joined: 15 Jun 2007
Posts: 504
Followers: 1

Kudos [?]: 9 [0], given: 0

 [#permalink] New post 05 Jul 2007, 07:38
Thanks for the explanation, I'm horrible at re-writing equations. :wall
CIO
CIO
User avatar
Joined: 09 Mar 2003
Posts: 463
Followers: 2

Kudos [?]: 35 [0], given: 0

 [#permalink] New post 07 Jul 2007, 08:56
OA is 6. Nice job everyone.
VP
VP
User avatar
Joined: 08 Jun 2005
Posts: 1146
Followers: 6

Kudos [?]: 139 [0], given: 0

 [#permalink] New post 07 Jul 2007, 09:08
ian7777 wrote:
OA is 6. Nice job everyone.


Nice problem ian7777 , thanks.

:-D
  [#permalink] 07 Jul 2007, 09:08
Display posts from previous: Sort by

Crazy Roots

  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®.