It is currently 19 Oct 2017, 05:58

### 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

# Is 1+x+x^2+x^3+x^4>1/(1-x)? 1). x>0 2). x<1

Author Message
Manager
Joined: 04 Sep 2006
Posts: 113

Kudos [?]: 62 [0], given: 0

Is 1+x+x^2+x^3+x^4>1/(1-x)? 1). x>0 2). x<1 [#permalink]

### Show Tags

04 Jun 2009, 11:34
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.

Is 1+x+x^2+x^3+x^4>1/(1-x)?
1). x>0
2). x<1

Kudos [?]: 62 [0], given: 0

Senior Manager
Joined: 16 Jan 2009
Posts: 354

Kudos [?]: 232 [0], given: 16

Concentration: Technology, Marketing
GMAT 1: 700 Q50 V34
GPA: 3
WE: Sales (Telecommunications)

### Show Tags

04 Jun 2009, 14:55
Is 1+x+x^2+x^3+x^4>1/(1-x)?

1). x>0
1+x+x^2+x^3+x^4=1.X
Where X= x+x^2+x^3+x^4

Case 1:
1/(1-x) will be –ve for x>1
So , 1+x+x^2+x^3+x^4>1/(1-x)

Case 2:
1/(1-x) will be +ve for x<1

INSUFFICIENT

2). x<1

1/(1-x) will be +ve for x<1
INSUFFICIENT

TOGETHER :
For 1>x>0
1/(1-x) will be +ve
INSUFFICIENT
IMO E
_________________

Lahoosaher

Kudos [?]: 232 [0], given: 16

Manager
Joined: 11 Aug 2008
Posts: 150

Kudos [?]: 54 [0], given: 8

### Show Tags

09 Jun 2009, 03:02
IMO C
1) with x=4 YES
With x=0.5 NO
2) with x=-3 YES
with x=0.5 NO
Together YES
Hence C
What 's the OA?

Kudos [?]: 54 [0], given: 8

Manager
Joined: 28 Jan 2004
Posts: 202

Kudos [?]: 28 [0], given: 4

Location: India

### Show Tags

09 Jun 2009, 23:11
E
Agree with amolsk11.

Kudos [?]: 28 [0], given: 4

Senior Manager
Joined: 15 Jan 2008
Posts: 280

Kudos [?]: 49 [0], given: 3

### Show Tags

10 Jun 2009, 01:26
IMO E too..

1+x+x2+x3+X4 < 1 / (1-x) for x = 0.1

1/(1-x) = 1/ 0.9 = 1.1111111

1+x+x2+x3+x4 = 1+ .1 + .01+.001 = 1.1111

but for x = 0.5, the equation doesnt hold good.

1/(1-x) = 1/0.5 = 2

1+0.5+0.25+0.625 = 2.15 > 2

hence E

Kudos [?]: 49 [0], given: 3

Re: DS   [#permalink] 10 Jun 2009, 01:26
Display posts from previous: Sort by

# Is 1+x+x^2+x^3+x^4>1/(1-x)? 1). x>0 2). x<1

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne 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®.