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

It is currently 25 Jul 2014, 01:15

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

Gmatprep - sequence

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
User avatar
Joined: 04 Feb 2007
Posts: 29
Followers: 0

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

Gmatprep - sequence [#permalink] New post 08 Feb 2007, 19:54
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

50% (00:00) correct 50% (02:04) wrong based on 2 sessions
OA : [color=violet]C
Attachments

24.JPG
24.JPG [ 44.38 KiB | Viewed 2663 times ]

Senior Manager
Senior Manager
User avatar
Joined: 04 Jan 2006
Posts: 280
Followers: 1

Kudos [?]: 17 [0], given: 0

GMAT Tests User
 [#permalink] New post 08 Feb 2007, 20:03
Question: Given x1, x2, x3, ...; What is x1?

...(1) Xi = Xi-1/2
e.g. X2 = X1/2, X3 = X2/2
No number to find x1. INSUFF

...(2) x5 = x4/(x4 + 1)
No number to find x1. INSUFF

...(1) + (2);

Now we know the format Xi = Xi-1/2
and X5 = X4/(X4+1)

Clearly, X4 + 1 = 2
X4 = 2-1 = 1

X4 = (X3)/2 = 1; X3 = 2
X3 = (X2)/2 = 2; X2 = 4
..Keep going and you will know X1. Thus, (1) + (2) SUFF.
1 KUDOS received
Manager
Manager
avatar
Joined: 10 Dec 2005
Posts: 112
Followers: 1

Kudos [?]: 3 [1] , given: 0

Re: Gmatprep - sequence [#permalink] New post 08 Feb 2007, 20:49
1
This post received
KUDOS
joyce wrote:
OA : [color=violet]C


From condition 1 we know x2 =x1/2 ==> x1 = 2x2 is not sufficient to give us the value of x1

From condition 2 we know x5 = x4/x4+1 hard to dervie what is the value of x1 from this hence not sufficient

condition 1 and 2 together

x5 = x4/2 = x4/x4 +1 ==> x4+1 = 2 ==> x4 = 1------ I

we also know from condition 1 that x4 = x3/2 = 1 (from I)

hence x3 = 2----II

again from condition 1 we know x3 = x2/2 = 2 (from II)
x2 = 4

we know x1 = 2x2 = 2*4 = 8

Hence answer is C
_________________

"Live as if you were to die tomorrow. Learn as if you were to live forever." - Mahatma Gandhi

Intern
Intern
avatar
Joined: 09 Sep 2007
Posts: 10
Followers: 0

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

Re: Gmatprep - sequence [#permalink] New post 17 Jun 2008, 09:40
Hi guys,
i was going thru this post and came across one question.

statement 1+2 gives us
x4/2 = x4/(x4+1)
here we are equating x4+1=2 => x4=1

why dont we cross multiply here which gives us x4=0 or 1?
Intern
Intern
avatar
Joined: 22 Jun 2009
Posts: 2
Followers: 0

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

Re: Gmatprep - sequence [#permalink] New post 29 Jun 2009, 12:52
There are two possible values based on how you solved for X4. However, the question stem says the progression consists only of positive numbers. 0 is neither positive nor negative (it is even though). Hence you can rule out X4=0 as in invalid solution and proceed with X4.
Re: Gmatprep - sequence   [#permalink] 29 Jun 2009, 12:52
    Similar topics Author Replies Last post
Similar
Topics:
1 GMATprep: Sequence melissawlim 6 19 Dec 2009, 05:29
Experts publish their posts in the topic GMATPrep sequence Nihit 9 13 Jun 2008, 00:21
DS - GMATPrep - Sequence suniluic 12 28 Apr 2007, 17:09
Gmatprep - sequence joyce 1 05 Mar 2007, 13:11
DS:GMATPRep..sequence rkatl 8 07 Oct 2006, 08:20
Display posts from previous: Sort by

Gmatprep - sequence

  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®.