It is currently 22 Nov 2017, 17:25

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

In the xy-plane, if line k has negative slope, is the

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Manager
Manager
avatar
Joined: 06 Oct 2010
Posts: 56

Kudos [?]: 79 [0], given: 19

In the xy-plane, if line k has negative slope, is the [#permalink]

Show Tags

New post 15 Apr 2011, 20:19
00:00
A
B
C
D
E

Difficulty:

  85% (hard)

Question Stats:

33% (00:56) correct 67% (01:15) wrong based on 33 sessions

HideShow timer Statistics

In the xy-plane, if line k has negative slope, is the y-intercept of line k positive?

(1) The x-intercept of line k is less than the y-intercept of line k.
(2) The slope of line k is less than -2.

OPEN DISCUSSION OF THIS QUESTION IS HERE: in-the-xy-plane-if-line-k-has-negative-slope-is-the-129055.html
[Reveal] Spoiler: OA

Last edited by skbjunior on 16 Apr 2011, 04:15, edited 1 time in total.

Kudos [?]: 79 [0], given: 19

Manager
Manager
avatar
Joined: 18 Jan 2011
Posts: 228

Kudos [?]: 37 [0], given: 4

Re: DS Coordinate Geom [#permalink]

Show Tags

New post 15 Apr 2011, 21:03
If the answer is A, I can explain.
_________________

Good Luck!!!

***Help and be helped!!!****

Kudos [?]: 37 [0], given: 4

1 KUDOS received
Math Forum Moderator
avatar
Joined: 20 Dec 2010
Posts: 1965

Kudos [?]: 2097 [1], given: 376

Re: DS Coordinate Geom [#permalink]

Show Tags

New post 15 Apr 2011, 21:15
1
This post received
KUDOS
1
This post was
BOOKMARKED
skbjunior wrote:
In the xy-plane, if line k has negative slope, is the y-intercept of line k positive?

(1) The x-intercept of line k is less than the y-intercept of line k.

(2) The slope of line k is less than -2.

Please provide explanation. I will provide OA soon. Thanks!


(1) Not Sufficient.
Attachment:
x_intercept_less_than_y.png
x_intercept_less_than_y.png [ 8.46 KiB | Viewed 1820 times ]


(2)Not Sufficient.
Attachment:
slope_less_than_minus_2.png
slope_less_than_minus_2.png [ 8.55 KiB | Viewed 1820 times ]


(3)Combining both.
It should always be to the right of the blue line.
Sufficient.

Attachment:
combining_both.png
combining_both.png [ 7.34 KiB | Viewed 1822 times ]


Ans: "C"

\(y=-2x+C\)

y-intercept
\(y=C\)

x-intercept
\(x=\frac{C}{2}\)

\(C>\frac{C}{2}\)
\(C-\frac{C}{2}>0\)
\(2C-C>0\)
\(C>0\)

Even for a slope of "-2", the y-intercept C has to be more than "0" or +ve to satisfy both statements.
_________________

~fluke

GMAT Club Premium Membership - big benefits and savings

Kudos [?]: 2097 [1], given: 376

2 KUDOS received
TOEFL Forum Moderator
avatar
Joined: 16 Nov 2010
Posts: 1603

Kudos [?]: 601 [2], given: 40

Location: United States (IN)
Concentration: Strategy, Technology
Premium Member Reviews Badge
Re: DS Coordinate Geom [#permalink]

Show Tags

New post 15 Apr 2011, 21:24
2
This post received
KUDOS
My take (1) and (2) are insufficient :

Y = mx + b

x intercept = -b/m
y intercept = b

-b/m < b

m < -2 => m is negative so -m is positive

b/(positive #) < b

=> b is positive (otherwise if b is negative, its magnitude will increase in smaller slices, also m is not a proper fraction, so that a negative # divided by proper positive fraction will increase in magnitude)

Answer - C
_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings

Kudos [?]: 601 [2], given: 40

Re: DS Coordinate Geom   [#permalink] 15 Apr 2011, 21:24
Display posts from previous: Sort by

In the xy-plane, if line k has negative slope, is the

  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®.