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

It is currently 26 Jul 2014, 09:18

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Line m passes through the origin. Line l is parallel to line

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 29 Nov 2011
Posts: 81
Followers: 1

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

Line m passes through the origin. Line l is parallel to line [#permalink] New post 18 Mar 2012, 20:38
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

50% (01:22) correct 50% (01:03) wrong based on 35 sessions
Line m passes through the origin. Line l is parallel to line m. What are the equations of the two lines?

(1) The horizontal distance between the two lines is 5 units.

(2) Line l has a y-intercept of 2.5

Last edited by Bunuel on 19 Mar 2012, 00:07, edited 2 times in total.
Edited the question.
Intern
Intern
avatar
Joined: 15 Feb 2012
Posts: 8
Location: India
Concentration: General Management, Operations
Schools: ISB '14
GPA: 3.09
WE: Operations (Manufacturing)
Followers: 0

Kudos [?]: 6 [0], given: 14

GMAT Tests User
Re: DS Coordinate [#permalink] New post 18 Mar 2012, 22:50
Smita04 wrote:
Line m passes through the origin. Line l is parallel to line m. What are the equations of the two lines?

(1) The horizontal distance between the two lines is 5 units.

(2) Line l has a y-intercept of 2.5


Since the lines are parallel the slopes would be same, say m
Let the Line M be y=mx
So line L will be y=mx+c

Statement 1
Considering the horizontal distance on x axis , this distance can be taken towards +ve or -ve side of origin.
So the slopes of the lines and the value of c cannot be determined.
So insufficient.

Statement 2
Now we know the value of c but we still don't know the value of slope.
So insufficient.

From 1+2
We know that horizontal distance is 5 i.e x intercept and y intercept is 2.5 i.e c=2.5
Since the y intercept is +ve ,horizontal distance i.e x intercept is -ve.
So the line passes through (-5,0)
therefore using the equation we get
0=m(-5)+2.5
or m=1/2
So the equations are y=0.5x
and y=0.5x+2.5
So the answer is C
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 18746
Followers: 3251

Kudos [?]: 22454 [0], given: 2619

Re: Line m passes through the origin. Line l is parallel to line [#permalink] New post 19 Mar 2012, 00:06
Expert's post
Line m passes through the origin. Line l is parallel to line m. What are the equations of the two lines?

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

From the stem:
Since parallel lines have the same slope, then the slopes of l and m are the same;
Since a line passing through the origin has y-intercept equal to zero then the equation of line m would be y_m=mx and the equation of line l would be y_l=mx+b

(1) The horizontal distance between the two lines is 5 units --> basically we are told that the x-intercept of line l is either -5 or 5, so we know that line l passes either through the point (-5, 0) or (5, 0). Not sufficient.

(2) Line l has a y-intercept of 2.5 --> b=2.5, so we know that line l passes through the point (0, 2.5). One point is not enough to determine (fix) a line. Not sufficient.

(1)+(2) Now, even take together we cannot determine whether line l passes through the point (-5, 0) or (5, 0). So, we would have two possible points of line l: (-5, 0) and (0, 2.5) OR (5, 0) and (0, 2.5), which means that we would have two possible equations of line l and m: y_l=0.5*x+2.5 and y_m=0.5*x OR y_l=-0.5*x+2.5 and y_m=-0.5*x. Not sufficient.

Answer: E.

To demonstrate.
Case 1:
Attachment:
Case 1.png
Case 1.png [ 7.73 KiB | Viewed 2749 times ]

Case 2:
Attachment:
Case 2.png
Case 2.png [ 8.08 KiB | Viewed 2746 times ]

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

Hope it helps.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Intern
Intern
avatar
Joined: 15 Feb 2012
Posts: 8
Location: India
Concentration: General Management, Operations
Schools: ISB '14
GPA: 3.09
WE: Operations (Manufacturing)
Followers: 0

Kudos [?]: 6 [0], given: 14

GMAT Tests User
Re: Line m passes through the origin. Line l is parallel to line [#permalink] New post 19 Mar 2012, 00:45
Thanx Bunuel
made a blunder mistake ...
there is lot to learn from you...
I will not delete my post so that others could learn from my mistake.
Manager
Manager
avatar
Status: I will not stop until i realise my goal which is my dream too
Joined: 25 Feb 2010
Posts: 235
Schools: Johnson '15
Followers: 2

Kudos [?]: 20 [0], given: 16

GMAT Tests User
Re: Line m passes through the origin. Line l is parallel to line [#permalink] New post 19 Mar 2012, 07:03
fantastic reply from Brunel....thanks
_________________

Regards,
Harsha

Note: Give me kudos if my approach is right , else help me understand where i am missing.. I want to bell the GMAT Cat ;)

Satyameva Jayate - Truth alone triumphs

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 18746
Followers: 3251

Kudos [?]: 22454 [0], given: 2619

Re: Line m passes through the origin. Line l is parallel to line [#permalink] New post 27 Jun 2013, 21:30
Expert's post
Bumping for review and further discussion*. Get a kudos point for an alternative solution!

*New project from GMAT Club!!! Check HERE

Theory on Coordinate Geometry: math-coordinate-geometry-87652.html

All DS Coordinate Geometry Problems to practice: search.php?search_id=tag&tag_id=41
All PS Coordinate Geometry Problems to practice: search.php?search_id=tag&tag_id=62

_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Re: Line m passes through the origin. Line l is parallel to line   [#permalink] 27 Jun 2013, 21:30
    Similar topics Author Replies Last post
Similar
Topics:
3 If line L passes through PTK 4 31 Mar 2011, 04:45
4 Experts publish their posts in the topic If line l passes through point (m, n), is the slope of the banksy 8 15 Feb 2011, 12:12
The slope of a line that passes through origin and S is 1/2, zelilmaze 1 08 Sep 2006, 00:59
The slope of a line that passes through origin and S is 1/2, getzgetzu 3 26 Apr 2006, 02:30
In the xy plane, the line k passes through the origin and desiguy 3 10 Nov 2005, 07:04
Display posts from previous: Sort by

Line m passes through the origin. Line l is parallel to line

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

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®.