GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 13 Oct 2019, 19:03 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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.  In the x-y coordinate plane, does line k have a positive x-intercept?

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

Hide Tags

CEO  V
Joined: 12 Sep 2015
Posts: 3990
In the x-y coordinate plane, does line k have a positive x-intercept?  [#permalink]

Show Tags

1
Top Contributor
2 00:00

Difficulty:   55% (hard)

Question Stats: 61% (01:50) correct 39% (02:19) wrong based on 100 sessions

HideShow timer Statistics

In the x-y coordinate plane, does line k have a positive x-intercept?

(1) (slope of line k)(y-intercept of line k) > 0
(2) (slope of line k) - (y-intercept of line k) < 0

*kudos for all correct solutions

_________________
Director  G
Joined: 19 Oct 2013
Posts: 520
Location: Kuwait
GPA: 3.2
WE: Engineering (Real Estate)
In the x-y coordinate plane, does line k have a positive x-intercept?  [#permalink]

Show Tags

1
2
GMATPrepNow wrote:
In the x-y coordinate plane, does line k have a positive x-intercept?

(1) (slope of line k)(y-intercept of line k) > 0
(2) (slope of line k) - (y-intercept of line k) < 0

*kudos for all correct solutions

If the slope is positive then the y-intercept is positive only way for this to be possible is when x-intercept is negative.

The same is true for the slope is negative and y-intercept is negative

The x-intercept is negative.

Sufficient.

For statement 2)

If slope is positive then y intercept must be a larger positive for the statement to hold true and be negative.

If both are positive then x-intercept is negative.

Now if slope is negative then y-intercept is a smaller negative or a positive number.

X-intercept then can be positivbe or negative

Insufficient.

The answer is best understood by a drawing.

Thanks to GMATinsight for pointing out a mistake in my solution, I originally choose D.

Posted from my mobile device
Attachments

File comment: For statement 2 Screen Shot 2018-10-19 at 7.37.39 PM.png [ 31.78 KiB | Viewed 1023 times ]

File comment: For statement 1 Screen Shot 2018-10-19 at 7.37.33 PM.png [ 24.96 KiB | Viewed 1023 times ]

Originally posted by Salsanousi on 19 Oct 2018, 08:17.
Last edited by Salsanousi on 19 Oct 2018, 09:39, edited 2 times in total.
CEO  D
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2974
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Re: In the x-y coordinate plane, does line k have a positive x-intercept?  [#permalink]

Show Tags

GMATPrepNow wrote:
In the x-y coordinate plane, does line k have a positive x-intercept?

(1) (slope of line k)(y-intercept of line k) > 0
(2) (slope of line k) - (y-intercept of line k) < 0

*kudos for all correct solutions

Question: does line k have a positive x-intercept?

Statement 1: (slope of line k)(y-intercept of line k) > 0

Case 1: Both slope and y-intercept are +ve (Red Line)
Case 2: Both slope and y-intercept are -ve (Blue Line) As per both cases, x-intercept is -ve hence
SUFFICIENT

Statement 2: (slope of line k) - (y-intercept of line k) < 0

i.e. (slope of line k) < (y-intercept of line k)
Case 1: Y-intercept = 3 and slope = 1 (Red Line)
Case 2: Y-intercept = 3 and slope = -1 (Blue Line) X intercept in one case is +ve and in other case it's -ve hence
NOT SUFFICIENT

_________________
Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
CEO  D
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2974
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Re: In the x-y coordinate plane, does line k have a positive x-intercept?  [#permalink]

Show Tags

Salsanousi wrote:
GMATPrepNow wrote:
In the x-y coordinate plane, does line k have a positive x-intercept?

(1) (slope of line k)(y-intercept of line k) > 0
(2) (slope of line k) - (y-intercept of line k) < 0

*kudos for all correct solutions

If the slope is positive then the y-intercept is positive only way for this to be possible is when x-intercept is negative.

The same is true for the slope is negative and y-intercept is negative

The x-intercept is negative.

Sufficient.

For statement 2)

If slope is positive then y intercept must be a larger positive for the statement to hold true and be negative.

If both are positive then x-intercept is negative.

Now if slope is negative then y-intercept must be a smaller negative.

X-intercept is negative.

Sufficient.

The answer is best understood by a drawing.

Posted from my mobile device

I find some mistake in highlighted part Salsanousi

When slope is -1, Y-intercept may be +3 as well and (slope of line k) - (y-intercept of line k) = (-1) - (+3) < 0 also stays satisfied.
_________________
Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
Director  G
Joined: 19 Oct 2013
Posts: 520
Location: Kuwait
GPA: 3.2
WE: Engineering (Real Estate)
Re: In the x-y coordinate plane, does line k have a positive x-intercept?  [#permalink]

Show Tags

GMATinsight thanks!! I missed that out :/

Posted from my mobile device
CEO  V
Joined: 12 Sep 2015
Posts: 3990
Re: In the x-y coordinate plane, does line k have a positive x-intercept?  [#permalink]

Show Tags

1
Top Contributor
GMATPrepNow wrote:
In the x-y coordinate plane, does line k have a positive x-intercept?

(1) (slope of line k)(y-intercept of line k) > 0
(2) (slope of line k) - (y-intercept of line k) < 0

*kudos for all correct solutions

Target question: Does line k have a positive x-intercept?

Statement 1: (slope of line k)(y-intercept of line k) > 0
There are two possible cases that that satisfy statement 1:
- the slope and y-intercept are both positive
- the slope and y-intercept are both negative
Let's examine each case:

Case a: the slope and y-intercept are both positive
No matter now you sketch a line that has these two features, it will look something like this: As you can see, the answer to the target question is NO, line k does NOT have a positive x-intercept

Case b: the slope and y-intercept are both negative.
No matter now you sketch a line that has these two features, it will look something like this: As you can see, the answer to the target question is NO, line k does NOT have a positive x-intercept

In both cases, the answer to the target question is the SAME.
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: (slope of line k) - (y-intercept of line k) < 0
There are several lines that satisfy statement 2. Here are two:
Case a:The line has a slope of -2 and y-intercept of -1 . In this case, the answer to the target question is NO, line k does NOT have a positive x-intercept

Case b: The line has a slope of -2 and y-intercept of 1 . In this case, the answer to the target question is YES, line k DOES have a positive x-intercept

Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Cheers,
Brent
_________________
Manager  S
Joined: 26 Nov 2018
Posts: 96
Concentration: Technology, Entrepreneurship
GPA: 3.3
WE: Manufacturing and Production (Manufacturing)
In the x-y coordinate plane, does line k have a positive x-intercept?  [#permalink]

Show Tags

GMATinsight wrote:
Salsanousi wrote:
GMATPrepNow wrote:
In the x-y coordinate plane, does line k have a positive x-intercept?

(1) (slope of line k)(y-intercept of line k) > 0
(2) (slope of line k) - (y-intercept of line k) < 0

*kudos for all correct solutions

If the slope is positive then the y-intercept is positive only way for this to be possible is when x-intercept is negative.

The same is true for the slope is negative and y-intercept is negative

The x-intercept is negative.

Sufficient.

For statement 2)

If slope is positive then y intercept must be a larger positive for the statement to hold true and be negative.

If both are positive then x-intercept is negative.

Now if slope is negative then y-intercept must be a smaller negative.

X-intercept is negative.

Sufficient.

The answer is best understood by a drawing.

Posted from my mobile device

I find some mistake in highlighted part Salsanousi

When slope is -1, Y-intercept may be +3 as well and (slope of line k) - (y-intercept of line k) = (-1) - (+3) < 0 also stays satisfied.

I am not clear the below statement that you have mentioned above. Kindly help me how it happens.

If the slope is positive then the y-intercept is positive only way for this to be possible is when x-intercept is negative. In the x-y coordinate plane, does line k have a positive x-intercept?   [#permalink] 11 Feb 2019, 01:28
Display posts from previous: Sort by

In the x-y coordinate plane, does line k have a positive x-intercept?

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne  