Find all School-related info fast with the new School-Specific MBA Forum
Learn more about the recent changes... close

It is currently 18 Jun 2013, 21:14
Customize  |  Hide

Search
Register
New posts
Unanswered

Does the line pass through the first quadrant? I. the line

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Current Student
User avatar
Joined: 31 Aug 2007
Posts: 374
Followers: 1

Kudos [?]: 36 [0], given: 1

GMAT Tests User
Does the line pass through the first quadrant? I. the line [#permalink] New post 10 Jan 2008, 11:27
00:00

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Does the line pass through the first quadrant?
I. the line has x-intercept=-1
II. the slope of the line is greater than 1

I went for B until someone mentioned that the slope could be infinitely large and hence a vertical line, so E...is that latter point legitimate as far as the gmat is concerned?
Kaplan Promo CodeKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
Director
Director
User avatar
Joined: 12 Jul 2007
Posts: 875
Followers: 8

Kudos [?]: 137 [0], given: 0

GMAT Tests User
Re: DS technical question [#permalink] New post 10 Jan 2008, 11:40
Image

We're trying to find out if a line cuts through the first quadrant (top right).

ALL lines with a positive slope will cross through the first quadrant
SOME lines with a negative slope will cross through the first quadrant

I. the line has x-intercept=-1

Tells us that the line crosses the x axis at (-1,0). Whether it passes through the first quadrant depends on it's slope, which we don't have, so this statement is insufficient.

INSUFFICIENT

II. the slope of the line is greater than 1

Tells us that the line has a positive slope, so it WILL pass through the first quadrant.

SUFFICIENT

AnswerB

A vertical line has an undefined slope because slope = rise/run and a vertical line has a run of 0 (and you can't divide by 0) so the slope is undefined. A horizontal line has a slope of 0. The fact that statement 2 says it has a slope greater than 1 tells us it's not a vertical or horizontal line, and that it does cross the first quadrant at some point.
Director
Director
Joined: 09 Jul 2005
Posts: 595
Followers: 2

Kudos [?]: 15 [0], given: 0

GMAT Tests User
Re: DS technical question [#permalink] New post 10 Jan 2008, 11:52
eschn3am wrote:
Image

We're trying to find out if a line cuts through the first quadrant (top right).

ALL lines with a positive slope will cross through the first quadrant
SOME lines with a negative slope will cross through the first quadrant

I. the line has x-intercept=-1

Tells us that the line crosses the x axis at (-1,0). Whether it passes through the first quadrant depends on it's slope, which we don't have, so this statement is insufficient.

INSUFFICIENT

II. the slope of the line is greater than 1

Tells us that the line has a positive slope, so it WILL pass through the first quadrant.

SUFFICIENT

AnswerB

A vertical line has an undefined slope because slope = rise/run and a vertical line has a run of 0 (and you can't divide by 0) so the slope is undefined. A horizontal line has a slope of 0. The fact that statement 2 says it has a slope greater than 1 tells us it's not a vertical or horizontal line, and that it does cross the first quadrant at some point.


I do not agree with you. The fact that slope of a line is infinity does not mean that the value of the slope does not exit. The slope of the line x=-1 exits and is greater than 1 and it doesn't cross quadrant I. OA should be E.
Director
Director
User avatar
Joined: 12 Jul 2007
Posts: 875
Followers: 8

Kudos [?]: 137 [0], given: 0

GMAT Tests User
Re: DS technical question [#permalink] New post 10 Jan 2008, 11:57
Quote:
I do not agree with you. The fact that slope of a line is infinity does not mean that the value of the slope does not exit. The slope of the line x=-1 exits and is greater than 1 and it doesn't cross quadrant I. OA should be E.


Quote:
Verdict: vertical lines have NO SLOPE. That is, the concept of slope just doesn't work for vertical lines. The slope doesn't exist!

http://www.purplemath.com/modules/slope.htm

Well I'm afraid the entire math community agrees with me so I'll stick with B.
CEO
CEO
User avatar
Joined: 17 Nov 2007
Posts: 3608
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 240

Kudos [?]: 1322 [0], given: 347

GMAT ToolKit User GMAT Tests User
Re: DS technical question [#permalink] New post 10 Jan 2008, 12:11
The answer lies in the plane of math definitions.
http://en.wikipedia.org/wiki/Slope

"The larger the absolute value of a slope, the steeper the line. A horizontal line has slope 0, a 45° rising line has a slope of +1, and a 45° falling line has a slope of -1. A vertical line's slope is undefined."

I think it origins from a more general math definition: Division by zero.
http://en.wikipedia.org/wiki/Division_(mathematics)

Division by zero (i.e. where the divisor is zero) is not defined.
_________________

NEW! GMAT ToolKit 2 (iOS) / GMAT ToolKit (Android) - The must have GMAT prep app | PrepGame

Director
Director
Joined: 09 Jul 2005
Posts: 595
Followers: 2

Kudos [?]: 15 [0], given: 0

GMAT Tests User
Re: DS technical question [#permalink] New post 10 Jan 2008, 14:16
walker wrote:
The answer lies in the plane of math definitions.
http://en.wikipedia.org/wiki/Slope

"The larger the absolute value of a slope, the steeper the line. A horizontal line has slope 0, a 45° rising line has a slope of +1, and a 45° falling line has a slope of -1. A vertical line's slope is undefined."

I think it origins from a more general math definition: Division by zero.
http://en.wikipedia.org/wiki/Division_(mathematics)

Division by zero (i.e. where the divisor is zero) is not defined.


OG also agree with you guys. What is the source of this question?
Re: DS technical question   [#permalink] 10 Jan 2008, 14:16
    Similar topics Author Replies Last post
Similar
Topics:
 New posts Does the line pass through the first quadrant? I. the line joemama142000 8 24 Mar 2006, 20:47
Popular new posts Does the line pass through Ist quadrant? 1) The intercept getzgetzu 17 27 Apr 2006, 23:45
Popular new posts Does line k pass through center of the circle? I) The circle zelilmaze 14 08 Sep 2006, 02:01
New posts 3 If line L passes through PTK 4 31 Mar 2011, 05:45
New posts 4 Experts publish their posts in the topic The line 3x + 4y = 8 passes through all of the quadrants in venmic 2 09 Oct 2012, 12:28
Display posts from previous: Sort by

Does the line pass through the first quadrant? I. the line

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: VeritasPrepKarishma, Bunuel, IanStewart

Search for:


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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com