It is currently 19 Sep 2017, 08:32

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If k does not equal 0,1, or -1 is 1/k>0? (And why?) 1)

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 23 May 2008
Posts: 48

Kudos [?]: 93 [0], given: 0

If k does not equal 0,1, or -1 is 1/k>0? (And why?) 1) [#permalink]

Show Tags

New post 05 Dec 2008, 20:21
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If k does not equal 0,1, or -1 is 1/k>0? (And why?)

1) 1/(k-1)>0

2) 1/(k+1)>0

(GMAT practice test http://www.mba.com)

Kudos [?]: 93 [0], given: 0

Manager
Manager
avatar
Joined: 27 May 2008
Posts: 199

Kudos [?]: 45 [0], given: 0

Re: Data Sufficiency [#permalink]

Show Tags

New post 05 Dec 2008, 20:44
A

1) 1/(k-1)>0

k-1 < 0 ; k<1 so 1/k>1 SUFF

2) 1/(k+1)>0

k+1 <0 k< -1 ; 1/k >-1 IN SUFF

Kudos [?]: 45 [0], given: 0

1 KUDOS received
Intern
Intern
avatar
Joined: 05 Dec 2008
Posts: 20

Kudos [?]: 6 [1], given: 0

Re: Data Sufficiency [#permalink]

Show Tags

New post 06 Dec 2008, 10:54
1
This post received
KUDOS
Another way (possibly easier) to read the question "is 1/k > 0?" is "is k positive?"
That's what the question is really asking since the only way for 1/k to be greater than zero (i.e., positive) is for b to be positive.
We can also read our data this way. So now we get a slightly new question:
If k does not equal 0,1, or -1 is k positive?
(1) 1/(k-1) is positive
(2) 1/(k+1)is positive


(1) if 1/k-1 is positive then it must be the case that k-1 is positive.
If k-1 is positive, then k must be greater than 1 (i.e., k>1)
Is this enough information to determine whether k is positive? You bet.

(2) if 1/k+1 is positive then it must be the case that k+1 is positive.
If k+1 is positive, then k must be greater than -1 (i.e., k>-1)
Is this enough information to determine whether k is positive?
No. k could equal -0.5 or it could equal 3

The correct answer is A

Kudos [?]: 6 [1], given: 0

Intern
Intern
avatar
Joined: 23 May 2008
Posts: 48

Kudos [?]: 93 [0], given: 0

Re: Data Sufficiency [#permalink]

Show Tags

New post 08 Dec 2008, 11:51
Thanks for both those explanations. That helps a lot. It is good to see how to figure it in a few different ways.

Kudos [?]: 93 [0], given: 0

Re: Data Sufficiency   [#permalink] 08 Dec 2008, 11:51
Display posts from previous: Sort by

If k does not equal 0,1, or -1 is 1/k>0? (And why?) 1)

  post reply Question banks Downloads My Bookmarks Reviews Important topics  


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

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®.