It is currently 17 Oct 2017, 01:06

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

gmat prep DS : slopes

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Senior Manager
Senior Manager
avatar
Joined: 02 Dec 2007
Posts: 450

Kudos [?]: 288 [0], given: 6

gmat prep DS : slopes [#permalink]

Show Tags

New post 26 Sep 2008, 12:40
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

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.

Attachment:
slopes.JPG
slopes.JPG [ 75.79 KiB | Viewed 982 times ]

Kudos [?]: 288 [0], given: 6

Intern
Intern
avatar
Joined: 20 Aug 2008
Posts: 27

Kudos [?]: 2 [0], given: 0

Re: gmat prep DS : slopes [#permalink]

Show Tags

New post 30 Sep 2008, 12:47
Hi,

You actually need to draw this figure.

C is correct, The reason is from the first statement the two lines, would either cross the X axis at a point where x>0 or here x<0. In both the cases we cannot determine what would be the product of the slopes.

Coming to 2nd statement since it is negative, it means that one line crosses the y axis at a point where y>0 and the other line crosses the y axis at a point where y<0. This situation alone cant help. If we combine both, then you will find that it is possible only when x>0 - from teh inference of statement 1. best , is if you can draw a diagram.


Award points if you feel. Let me know for any further clarifications

Regards,
Max

Kudos [?]: 2 [0], given: 0

1 KUDOS received
Intern
Intern
avatar
Joined: 29 Sep 2008
Posts: 46

Kudos [?]: 9 [1], given: 0

Re: gmat prep DS : slopes [#permalink]

Show Tags

New post 30 Sep 2008, 13:04
1
This post received
KUDOS
the basic equation of a line is y = mx + c. where the slope is m, y-intercept is c and x-intercept is -c/m
let's say:

l is y = m1x + c1 with y-intercept = c1 and x-intercept = -c1/m1
k is y = m2x + c2 with y-intercept = c2 and x-intercept = -c2/m2

statement I - c1c2/m1m2 > 0. does not say anything about c1c2 so we cannot say if m1m2 is negative or not

statement I - c1c2 < 0. does not say anything about m1 and m2 so we cannot say if m1m2 is negative or not.

I and II - if c1c2 < 0 then m1m2 has to be negative.

Thus C

Kudos [?]: 9 [1], given: 0

VP
VP
User avatar
Joined: 05 Jul 2008
Posts: 1402

Kudos [?]: 437 [0], given: 1

Re: gmat prep DS : slopes [#permalink]

Show Tags

New post 30 Sep 2008, 19:38
aim2010 wrote:
the basic equation of a line is y = mx + c. where the slope is m, y-intercept is c and x-intercept is -c/m
let's say:

l is y = m1x + c1 with y-intercept = c1 and x-intercept = -c1/m1
k is y = m2x + c2 with y-intercept = c2 and x-intercept = -c2/m2

statement I - c1c2/m1m2 > 0. does not say anything about c1c2 so we cannot say if m1m2 is negative or not

statement I - c1c2 < 0. does not say anything about m1 and m2 so we cannot say if m1m2 is negative or not.

I and II - if c1c2 < 0 then m1m2 has to be negative.

Thus C


This is what I did. How ever, I was wondering (4,3) were never used when I solved. Then I started thinking Did I miss some thing here?

What is the OA?

Kudos [?]: 437 [0], given: 1

Intern
Intern
avatar
Joined: 29 Sep 2008
Posts: 46

Kudos [?]: 9 [0], given: 0

Re: gmat prep DS : slopes [#permalink]

Show Tags

New post 30 Sep 2008, 21:52
icandy wrote:
aim2010 wrote:
the basic equation of a line is y = mx + c. where the slope is m, y-intercept is c and x-intercept is -c/m
let's say:

l is y = m1x + c1 with y-intercept = c1 and x-intercept = -c1/m1
k is y = m2x + c2 with y-intercept = c2 and x-intercept = -c2/m2

statement I - c1c2/m1m2 > 0. does not say anything about c1c2 so we cannot say if m1m2 is negative or not

statement I - c1c2 < 0. does not say anything about m1 and m2 so we cannot say if m1m2 is negative or not.

I and II - if c1c2 < 0 then m1m2 has to be negative.

Thus C


This is what I did. How ever, I was wondering (4,3) were never used when I solved. Then I started thinking Did I miss some thing here?

What is the OA?


The point is given as a trap to attract people to draw lines and form cases and waste time. without the point too the question would remain the same, just that when they find no other way, people would straightaway jump to the equation based approach. Just my feeling, I might be terribly wrong.
OA is C, see image in the first post.

Kudos [?]: 9 [0], given: 0

Re: gmat prep DS : slopes   [#permalink] 30 Sep 2008, 21:52
Display posts from previous: Sort by

gmat prep DS : slopes

  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®.