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

It is currently 19 Apr 2014, 14:10

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

Lines n and p lie in the xy-plane. Is the slope of line n

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Intern
Intern
User avatar
Joined: 20 Feb 2012
Posts: 43
Followers: 1

Kudos [?]: 30 [1] , given: 6

Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 23 Feb 2012, 07:07
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

  25% (low)

Question Stats:

67% (01:54) correct 32% (01:07) wrong based on 155 sessions
Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p ?

(1) Lines n and p intersect at the point (5 , 1).
(2) The y-intercept of line n is greater than the y-intercept of line p.
[Reveal] Spoiler: OA
11 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 17321
Followers: 2875

Kudos [?]: 18401 [11] , given: 2350

GMAT Tests User CAT Tests
Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 23 Feb 2012, 07:11
11
This post received
KUDOS
Expert's post
BANON wrote:
Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p ?

(1) Lines n and p intersect at the point (5 , 1).
(2) The y-intercept of line n is greater than the y-intercept of line p.


Algebraic approach:

Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p?

We have two lines: y_n=m_1x+b_1 and y_p=m_2x+b_2. Q: m_1<m_2 true?

(1) Lines n and p intersect at the point (5,1) --> 1=5m_1+b_1=5m_2+b_2 --> 5(m_1-m_2)=b_2-b_1. Not sufficient.

(2) The y-intercept of line n is greater than the y-intercept of line p --> y-intercept is value of y for x=0, so it's the value of b --> b_1>b_2 or b_2-b_1<0. Not sufficient.

(1)+(2) 5(m_1-m_2)=b_2-b_1, as from (2) b_2-b_1<0 (RHS), then LHS (left hand side) also is less than zero 5(m_1-m_2)<0 --> m_1-m_2<0 --> m_1<m_2. Sufficient.

Answer: C.

For more on this topic 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

2 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 17321
Followers: 2875

Kudos [?]: 18401 [2] , given: 2350

GMAT Tests User CAT Tests
Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 23 Feb 2012, 07:13
2
This post received
KUDOS
Expert's post
BANON wrote:
Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p ?

(1) Lines n and p intersect at the point (5 , 1).
(2) The y-intercept of line n is greater than the y-intercept of line p.


Graphic approach:

Lines n and p lie in the xy plane. Is the slope of line n less than the slope of line p?

(1) Lines n and p intersect at (5,1)
(2) The y-intercept of line n is greater than y-intercept of line p

The two statements individually are not sufficient.

(1)+(2) Note that a higher absolute value of a slope indicates a steeper incline.

Now, if both lines have positive slopes then as the y-intercept of line n (blue) is greater than y-intercept of line p (red) then the line p is steeper hence its slope is greater than the slope of the line n:
Attachment:
1.PNG
1.PNG [ 14.29 KiB | Viewed 5126 times ]


If both lines have negative slopes then again as the y-intercept of line n (blue) is greater than y-intercept of line p (red) then the line n is steeper hence the absolute value of its slope is greater than the absolute value of the slope of the line p, so the slope of n is more negative than the slope of p, which means that the slope of p is greater than the slope of n:
Attachment:
2.PNG
2.PNG [ 13.66 KiB | Viewed 5116 times ]


So in both cases the slope of p is greater than the slope of n. Sufficient.

Answer: C.
_________________

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

Intern
Intern
Joined: 04 Jan 2012
Posts: 8
GPA: 3.97
WE: Analyst (Mutual Funds and Brokerage)
Followers: 0

Kudos [?]: 0 [0], given: 12

Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 23 Feb 2012, 08:05
Bunuel,

What if line p has a negative y intercept but line n has a positive intercept? Wouldn't that give the oposite answer?
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 17321
Followers: 2875

Kudos [?]: 18401 [0], given: 2350

GMAT Tests User CAT Tests
Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 23 Feb 2012, 09:13
Expert's post
nglekel wrote:
Bunuel,

What if line p has a negative y intercept but line n has a positive intercept? Wouldn't that give the oposite answer?




If line p has a negative y-intercept then its slope is positive and it will still be more than the slope of n, with positive y-intercept (if the slope of n will be positive than p will still be steeper than n, and if the slope of n is negative it obviously will be less than positive slope of p). Consider first image and rotate line n (blue) so that it to have positive y-intercept and you'll easily see the answer.

Check the following links for similar questions, where different scenarios are considered:
in-the-xy-plane-is-the-slope-of-line-l-greater-than-the-126941.html
if-the-slopes-of-the-line-l1-and-l2-are-of-the-same-sign-is-126759.html
slopes-of-m-and-n-124025.html

Also check Coordinate Geometry chapter of Math Book for theory on this subject: 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

Manager
Manager
Joined: 05 Jul 2012
Posts: 83
Location: India
Concentration: Finance, Strategy
GMAT Date: 09-30-2012
GPA: 3.08
WE: Engineering (Energy and Utilities)
Followers: 4

Kudos [?]: 16 [0], given: 8

Re: Lines n and p lie in the xy-plane. Is the slope of line n le [#permalink] New post 13 Sep 2012, 11:19
monikaleoster wrote:
Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p ?
(1) Lines n and p intersect at the point (5,1).
(2) The y-intercept of line n is greater than the y-intercept of line p.



Here we have two lines and two slopes
So lets first write the equations for our lovely lines

Y = mnX + Cn
Y = mpX + Cp

Now statement one says that it intersects at 5,1. SO lets put it in the equations and subtract them

We get, (mn-mp)5 = Cp-Cn that tells us nothing about the slopes of the lines or their relative values, but if we know the value of Cp-Cn that weather it is positive or negative we will know weathet mn-mp is positive or negative and that which is greater


Statement 2 Y intercept of line n is greater than p so that gives us Cn >Cp

Alone this statement is also not sufficient. it talks abou c not slopes

But if we combine the two, Voila !! we know which slope is greater.
Intern
Intern
Joined: 31 Oct 2011
Posts: 19
Schools: ESSEC '15 (A)
GMAT 1: 650 Q45 V35
Followers: 0

Kudos [?]: 9 [0], given: 2

Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 29 Dec 2012, 08:18
I don't get it :/

what if slope of line P is positive and the slope of line N negative (but still satisfying all the condition...)
Bunuel, on your examples the slopes have the same sign... are we talking about the absolute value of the slope?
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 17321
Followers: 2875

Kudos [?]: 18401 [0], given: 2350

GMAT Tests User CAT Tests
Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 27 Jun 2013, 21:29
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

Intern
Intern
Joined: 12 Mar 2013
Posts: 12
Followers: 0

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

Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 16 Jul 2013, 18:23
Bunuel wrote:
BANON wrote:
Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p ?

(1) Lines n and p intersect at the point (5 , 1).
(2) The y-intercept of line n is greater than the y-intercept of line p.


Algebraic approach:

Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p?

We have two lines: y_n=m_1x+b_1 and y_p=m_2x+b_2. Q: m_1<m_2 true?

(1) Lines n and p intersect at the point (5,1) --> 1=5m_1+b_1=5m_2+b_2 --> 5(m_1-m_2)=b_2-b_1. Not sufficient.
(2) The y-intercept of line n is greater than the y-intercept of line p --> y-intercept is value of y for x=0, so it's the value of b --> b_1>b_2 or b_2-b_1<0. Not sufficient.

(1)+(2) 5(m_1-m_2)=b_2-b_1, as from (2) b_2-b_1<0 (RHS), then LHS (left hand side) also is less than zero 5(m_1-m_2)<0 --> m_1-m_2<0 --> m_1<m_2. Sufficient.

Answer: C.



Hope it helps.


Bunuel,

In here - y_n=m_1x+b_1 and y_p=m_2x+b_2. Q: m_1<m_2 true?

Why have you chosen different variables for the y?

Shouldnt the two equations be y=m1x+b1 and y=m2x+b2? We always form the equation from the basic form of y=mx+c wherein we substitute the values of m and c. And if that is the case, we can get the answer from statement II only.

I know I am missing something but I am not clear as to why you have picked different variables for y but not for x.
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 17321
Followers: 2875

Kudos [?]: 18401 [0], given: 2350

GMAT Tests User CAT Tests
Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 16 Jul 2013, 22:08
Expert's post
keenys wrote:
Bunuel wrote:
BANON wrote:
Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p ?

(1) Lines n and p intersect at the point (5 , 1).
(2) The y-intercept of line n is greater than the y-intercept of line p.


Algebraic approach:

Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p?

We have two lines: y_n=m_1x+b_1 and y_p=m_2x+b_2. Q: m_1<m_2 true?

(1) Lines n and p intersect at the point (5,1) --> 1=5m_1+b_1=5m_2+b_2 --> 5(m_1-m_2)=b_2-b_1. Not sufficient.
(2) The y-intercept of line n is greater than the y-intercept of line p --> y-intercept is value of y for x=0, so it's the value of b --> b_1>b_2 or b_2-b_1<0. Not sufficient.

(1)+(2) 5(m_1-m_2)=b_2-b_1, as from (2) b_2-b_1<0 (RHS), then LHS (left hand side) also is less than zero 5(m_1-m_2)<0 --> m_1-m_2<0 --> m_1<m_2. Sufficient.

Answer: C.



Hope it helps.


Bunuel,

In here - y_n=m_1x+b_1 and y_p=m_2x+b_2. Q: m_1<m_2 true?

Why have you chosen different variables for the y?

Shouldnt the two equations be y=m1x+b1 and y=m2x+b2? We always form the equation from the basic form of y=mx+c wherein we substitute the values of m and c. And if that is the case, we can get the answer from statement II only.

I know I am missing something but I am not clear as to why you have picked different variables for y but not for x.


n and p are subscripts of y's, not variables.

y=m_1x+b_1 is equation of line n.
y=m_2x+b_2 is equation of line p.

I used subscripts simply to distinguish one equation from another.
_________________

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

Intern
Intern
Joined: 12 Mar 2013
Posts: 12
Followers: 0

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

Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 17 Jul 2013, 04:02
Bunuel wrote:
keenys wrote:
Bunuel wrote:

Algebraic approach:

Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p?

We have two lines: y_n=m_1x+b_1 and y_p=m_2x+b_2. Q: m_1<m_2 true?

(1) Lines n and p intersect at the point (5,1) --> 1=5m_1+b_1=5m_2+b_2 --> 5(m_1-m_2)=b_2-b_1. Not sufficient.
(2) The y-intercept of line n is greater than the y-intercept of line p --> y-intercept is value of y for x=0, so it's the value of b --> b_1>b_2 or b_2-b_1<0. Not sufficient.

(1)+(2) 5(m_1-m_2)=b_2-b_1, as from (2) b_2-b_1<0 (RHS), then LHS (left hand side) also is less than zero 5(m_1-m_2)<0 --> m_1-m_2<0 --> m_1<m_2. Sufficient.

Answer: C.



Hope it helps.


Bunuel,

In here - y_n=m_1x+b_1 and y_p=m_2x+b_2. Q: m_1<m_2 true?

Why have you chosen different variables for the y?

Shouldnt the two equations be y=m1x+b1 and y=m2x+b2? We always form the equation from the basic form of y=mx+c wherein we substitute the values of m and c. And if that is the case, we can get the answer from statement II only.

I know I am missing something but I am not clear as to why you have picked different variables for y but not for x.


n and p are subscripts of y's, not variables.

y=m_1x+b_1 is equation of line n.
y=m_2x+b_2 is equation of line p.

I used subscripts simply to distinguish one equation from another.


If that is the case then, from the above equations

we get b1=y-m1x and b2=y-m2x

Now from statement 2 we know that b1>b2...

therefore, y-m1x >y-m2x

which gives (m1-m2)x>0

So it can be proved from statement 2 only that m1>m2

Where am I going wrong?
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 17321
Followers: 2875

Kudos [?]: 18401 [0], given: 2350

GMAT Tests User CAT Tests
Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 17 Jul 2013, 05:07
Expert's post
keenys wrote:
Bunuel wrote:
keenys wrote:
Bunuel,

In here - y_n=m_1x+b_1 and y_p=m_2x+b_2. Q: m_1<m_2 true?

Why have you chosen different variables for the y?

Shouldnt the two equations be y=m1x+b1 and y=m2x+b2? We always form the equation from the basic form of y=mx+c wherein we substitute the values of m and c. And if that is the case, we can get the answer from statement II only.

I know I am missing something but I am not clear as to why you have picked different variables for y but not for x.


n and p are subscripts of y's, not variables.

y=m_1x+b_1 is equation of line n.
y=m_2x+b_2 is equation of line p.

I used subscripts simply to distinguish one equation from another.


If that is the case then, from the above equations

we get b1=y-m1x and b2=y-m2x

Now from statement 2 we know that b1>b2...

therefore, y-m1x >y-m2x

which gives (m1-m2)x>0

So it can be proved from statement 2 only that m1>m2

Where am I going wrong?


The y-intercept is the value of y for x=0. You should substitute x=0 into both equations.

So, the y-intercept of line n is b1 and the y-intercept of line p is b2, from (2) we only have that b1>b2.
_________________

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

VP
VP
User avatar
Status: I'm back and not stopping until I hit 760+
Joined: 06 Sep 2013
Posts: 1345
Location: United States
Concentration: Finance, General Management
Schools: Wharton '17
GPA: 3.5
WE: Corporate Finance (Investment Banking)
Followers: 7

Kudos [?]: 87 [0], given: 177

GMAT ToolKit User CAT Tests
Re: Lines n and p lie in the xy-plane. Is the slope of line n [#permalink] New post 28 Dec 2013, 04:57
Bunuel wrote:
BANON wrote:
Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of line p ?

(1) Lines n and p intersect at the point (5 , 1).
(2) The y-intercept of line n is greater than the y-intercept of line p.


Graphic approach:

Lines n and p lie in the xy plane. Is the slope of line n less than the slope of line p?

(1) Lines n and p intersect at (5,1)
(2) The y-intercept of line n is greater than y-intercept of line p

The two statements individually are not sufficient.

(1)+(2) Note that a higher absolute value of a slope indicates a steeper incline.

Now, if both lines have positive slopes then as the y-intercept of line n (blue) is greater than y-intercept of line p (red) then the line p is steeper hence its slope is greater than the slope of the line n:
Attachment:
1.PNG


If both lines have negative slopes then again as the y-intercept of line n (blue) is greater than y-intercept of line p (red) then the line n is steeper hence the absolute value of its slope is greater than the absolute value of the slope of the line p, so the slope of n is more negative than the slope of p, which means that the slope of p is greater than the slope of n:
Attachment:
2.PNG


So in both cases the slope of p is greater than the slope of n. Sufficient.

Answer: C.


So talking about the case with negative slopes here. OK so line 'n' is steeper hence it has a higher absolute value for slope right? Then because it is more negative then it is in fact smaller than the slope of line p.

So here we are saying that the slope is treated just as any number, which means considering its sign

Eg. Slope of an horizontal line will be higher than a negative slope right? Just cause if one does it algebraically one will encounter the comparison and absolute values are not used at all in slope formulae as far as I'm aware

Just wanted to get this straight

Please advice

Cheers!
J :)
Re: Lines n and p lie in the xy-plane. Is the slope of line n   [#permalink] 28 Dec 2013, 04:57
    Similar topics Author Replies Last post
Similar
Topics:
Popular new posts Lines n and p lie in the xy-plane. Is the slope of line n dinesh8 17 07 May 2006, 17:24
New posts lines n and p lie in the xy-plane. is the slope of line n lan583 4 24 Aug 2006, 14:31
New posts Lines n and p lie in the xy-plane. Is the slope of line n alimad 2 25 Sep 2006, 21:37
New posts 1 Lines n and p lie in the xy-plane. Is the slope of line n artshep 9 11 Nov 2006, 12:28
This topic is locked, you cannot edit posts or make further replies. New 1 Experts publish their posts in the topic Lines n and p lie in the xy plane. Is the slope of line n EnterMatrix 5 10 Jul 2010, 00:05
Display posts from previous: Sort by

Lines n and p lie in the xy-plane. Is the slope of line n

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.