In the x–y plane, what is the y–intercept of the line l? : GMAT Data Sufficiency (DS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 21 Jan 2017, 14:08

### 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

# In the x–y plane, what is the y–intercept of the line l?

Author Message
TAGS:

### Hide Tags

Director
Status: Finally Done. Admitted in Kellogg for 2015 intake
Joined: 25 Jun 2011
Posts: 536
Location: United Kingdom
GMAT 1: 730 Q49 V45
GPA: 2.9
WE: Information Technology (Consulting)
Followers: 74

Kudos [?]: 2970 [0], given: 217

In the x–y plane, what is the y–intercept of the line l? [#permalink]

### Show Tags

16 Feb 2012, 16:35
2
This post was
BOOKMARKED
00:00

Difficulty:

95% (hard)

Question Stats:

21% (02:10) correct 79% (01:03) wrong based on 80 sessions

### HideShow timer Statistics

In the x–y plane, what is the y–intercept of the line l?

(1) The slope of the line l is 3 times its y-intercept.
(2) The x–intercept of line l is –1/3

As the OA is not given, I have arrived at answer C i.e both statements together are sufficient to answer the question. Please see below what makes me say this. Please let me know whether I am right or wrong.

Equation of line y = mx+c ------------------------------(1). Question is asking to find C.

Considering Statement 1 ----> m = 3c. So putting this value of m in (1) above we get y = c(3x+1). Not sufficient.

Considering Statement 2 ---> x intercept is -1/3 i.e. y = -m/3+c. -------------------------------(2)
Can't solve for C. Therefore insufficient.

Combining the statement 1 & 2 and substituting the value of m = 3c from statement 1 into statement 2. y = -3c/3+c => c-c = 0 Therefore, y = 0. Therefore C is the right answer.
[Reveal] Spoiler: OA

_________________

Best Regards,
E.

MGMAT 1 --> 530
MGMAT 2--> 640
MGMAT 3 ---> 610
GMAT ==> 730

Last edited by Bunuel on 02 Jun 2012, 11:34, edited 2 times in total.
Edited the question and added the OA
Math Expert
Joined: 02 Sep 2009
Posts: 36590
Followers: 7092

Kudos [?]: 93355 [2] , given: 10557

Re: Y intercept of line l [#permalink]

### Show Tags

16 Feb 2012, 20:14
2
KUDOS
Expert's post
In the x–y plane, what is the y–intercept of the line l?

Equation of a line in point intercept form is $$y=mx+b$$, where: $$m$$ is the slope of the line; $$b$$ is the y-intercept of the line (the value of $$y$$ for $$x=0$$).

The question is $$b=?$$

(1) The slope of line l is 3 times its y-intercept --> $$m=3b$$. Not sufficient to calculate $$b$$.

(2) The x-intercept of line l is -1/3 --> x-intercept is the value of $$x$$ for $$y=0$$ --> $$0=-\frac{1}{3}m+b$$ --> $$m=3b$$. Same info as above. Not sufficient.

(1)+(2) Nothing new. Not sufficient.

For more on this issue please check Coordinate Geometry chapter of Math Book: math-coordinate-geometry-87652.html

Hope it helps.
_________________
Senior Manager
Joined: 23 Oct 2010
Posts: 386
Location: Azerbaijan
Concentration: Finance
Schools: HEC '15 (A)
GMAT 1: 690 Q47 V38
Followers: 21

Kudos [?]: 323 [0], given: 73

In the x–y plane, what is the y–intercept of the line l? [#permalink]

### Show Tags

02 Jun 2012, 08:47
revised.
I got it and have no question
_________________

Happy are those who dream dreams and are ready to pay the price to make them come true

I am still on all gmat forums. msg me if you want to ask me smth

Last edited by LalaB on 02 Jun 2012, 09:43, edited 1 time in total.
Senior Manager
Joined: 13 May 2011
Posts: 317
WE 1: IT 1 Yr
WE 2: Supply Chain 5 Yrs
Followers: 21

Kudos [?]: 252 [1] , given: 11

Re: In the xy-plane, what is the y-intercept of line? [#permalink]

### Show Tags

02 Jun 2012, 09:39
1
KUDOS
Say the line is:
Y=mX+b
The question is: b=?
Statement 1: m=3b, b=m/3, we do not know the value of m
so b cannot be determined. Insufficient

Statement2: by plugging in point (0, -1/3), we get
0=-m/3+b or m=3b. same as statement 1. Insufficient

Together: since, both are the same statement and both are insufficient, the answer is E.
Manager
Joined: 22 Sep 2015
Posts: 118
Followers: 3

Kudos [?]: 38 [0], given: 136

Re: In the x–y plane, what is the y–intercept of the line l? [#permalink]

### Show Tags

20 Dec 2015, 13:15
since the answer is confirmed at E, can the answer in the first post be updated? When I clicked E for my answer, it showed that the correct answer is C.
Re: In the x–y plane, what is the y–intercept of the line l?   [#permalink] 20 Dec 2015, 13:15
Similar topics Replies Last post
Similar
Topics:
13 In the xy-plane, line l passes through the point (-7, k). What is the 7 19 Jan 2015, 05:02
11 Lines r and s lie in the xy-plane. Is the y-intercept of lin 18 07 Jun 2013, 02:35
11 In the xy-plane, what is the slope of line l? 3 27 Feb 2012, 07:19
122 In the xy-plane, what is the y-intercept of line l? 19 28 Feb 2010, 19:51
9 In the x–y plane, what is the y–intercept of the line l? 6 24 Sep 2009, 17:11
Display posts from previous: Sort by