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

 It is currently 06 Jul 2015, 12:52

### 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

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

Author Message
TAGS:
Current Student
Joined: 31 Aug 2007
Posts: 371
Followers: 1

Kudos [?]: 63 [0], given: 1

Does the line pass through the first quadrant? I. the line [#permalink]  10 Jan 2008, 10:27
00:00

Difficulty:

(N/A)

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 Code Knewton GMAT Discount Codes GMAT Pill GMAT Discount Codes
Director
Joined: 12 Jul 2007
Posts: 864
Followers: 13

Kudos [?]: 224 [0], given: 0

Re: DS technical question [#permalink]  10 Jan 2008, 10:40

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

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
Joined: 09 Jul 2005
Posts: 595
Followers: 2

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

Re: DS technical question [#permalink]  10 Jan 2008, 10:52
eschn3am wrote:

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

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
Joined: 12 Jul 2007
Posts: 864
Followers: 13

Kudos [?]: 224 [0], given: 0

Re: DS technical question [#permalink]  10 Jan 2008, 10:57
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
Joined: 17 Nov 2007
Posts: 3574
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 414

Kudos [?]: 2245 [0], given: 359

Re: DS technical question [#permalink]  10 Jan 2008, 11:11
Expert's post
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.
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

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

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

Re: DS technical question [#permalink]  10 Jan 2008, 13:16
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, 13:16
Similar topics Replies Last post
Similar
Topics:
3 Line L is a line in the x-y plane. Does line L pass through the secon 4 23 Feb 2015, 02:32
1 Line m passes through the origin. Line l is parallel to line 6 18 Mar 2012, 20:38
In the xv-plane, the line k passes through the origin and 3 20 Jul 2007, 02:21
Does line k pass through center of the circle? I) The circle 14 08 Sep 2006, 01:01
In the xy plane, the line k passes through the origin and 3 10 Nov 2005, 07:04
Display posts from previous: Sort by