Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 03 Oct 2009
Posts: 91

If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
17 Nov 2009, 20:53
1
This post received KUDOS
5
This post was BOOKMARKED
Question Stats:
64% (02:06) correct
36% (01:09) wrong based on 172 sessions
HideShow timer Statistics
If Line k in the xyplane has equation y = mx + b, where m and b are constants, what is the slope of k? (1) k is parallel to the line with equation y = (1m)x + b +1. (2) k intersects the line with equation y = 2x + 3 at the point (2, 7) I think it is A... from 1st ..since two lines are parallel.... m = 1 m m =1/2
from 2nd line passes through 2,3 3 = 2 m + b..can't say ..
So answer should be A...throw some lights...
Regards, Rohit
Official Answer and Stats are available only to registered users. Register/ Login.
Last edited by Bunuel on 27 Jul 2015, 09:12, edited 1 time in total.
Renamed the topic, edited the question and added the OA.



Manager
Joined: 13 Aug 2009
Posts: 201

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
18 Nov 2009, 03:35
Rohit, I agree that the answer to this problem is A. Statement two is not sufficient to determining the slope.



Manager
Joined: 29 Oct 2009
Posts: 211

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
18 Nov 2009, 04:09
1
This post received KUDOS
KocharRohit wrote: If Line k in the xyplane has equation y = mx + b, where m and b are constants, what is the slope of k? (1) k is parallel to the line with equation y = (1m)x + b +1. (2) k intersects the line with equation y = 2x + 3 at the point (2, 7).
I think it is A... from 1st ..since two lines are parallel.... m = 1 m m =1/2
from 2nd line passes through 2,3 3 = 2 m + b..can't say ..
So answer should be A...throw some lights...
Regards, Rohit Perfectly valid reasoning.
_________________
Click below to check out some great tips and tricks to help you deal with problems on Remainders! http://gmatclub.com/forum/compilationoftipsandtrickstodealwithremainders86714.html#p651942
Word Problems Made Easy! 1) Translating the English to Math : http://gmatclub.com/forum/wordproblemsmadeeasy87346.html 2) 'Work' Problems Made Easy : http://gmatclub.com/forum/workwordproblemsmadeeasy87357.html 3) 'Distance/Speed/Time' Word Problems Made Easy : http://gmatclub.com/forum/distancespeedtimewordproblemsmadeeasy87481.html



Intern
Joined: 11 Oct 2009
Posts: 12

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
06 Jan 2010, 21:24
I'm looking at and have a bit of a problem with data sufficiency question 94, of page 281 of the 12th edition of the official GMAT review where it says:
If line k in the xyplane has equation y= mx + b, where m and b are constants, what is the slope of k?
(1) k is parallel to the line with equation y= (1m)x + b + 1
Apparently the answer says that statement (1) alone is sufficient because the slope of line k and the other line are the same since the two lines are parallel, and thus m= 1  m, and therefore m= 1/2.
I understand that the two lines will have the same slope since they're parralell, but does no one else see the impossibility of setting m = 1m ??
If m is a constant or variable, it cannot possibly equal 1 minus itself, no? That's like saying 5 = 1  5.



Manager
Joined: 04 Feb 2007
Posts: 85

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
07 Jan 2010, 00:09
glender wrote: I'm looking at and have a bit of a problem with data sufficiency question 94, of page 281 of the 12th edition of the official GMAT review where it says:
If line k in the xyplane has equation y= mx + b, where m and b are constants, what is the slope of k?
(1) k is parallel to the line with equation y= (1m)x + b + 1
Apparently the answer says that statement (1) alone is sufficient because the slope of line k and the other line are the same since the two lines are parallel, and thus m= 1  m, and therefore m= 1/2.
I understand that the two lines will have the same slope since they're parralell, but does no one else see the impossibility of setting m = 1m ??
If m is a constant or variable, it cannot possibly equal 1 minus itself, no? That's like saying 5 = 1  5. m = 1 m add m to both sides: 2m = 1 divide by 2 to both sides: m = 1/2 the equation holds only for 1/2, not any value. Plug in 1/2 into the equation and you see it holds true.
_________________
If you like my post, a kudos is always appreciated



Intern
Joined: 11 Nov 2009
Posts: 1

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
07 Jan 2010, 05:35
Hi Glender, If two lines are parallel then each of the two lines cut the x axis at same angle. Hence we can say that slopes will be equal.
Form the above given two equations we can take the slopes of those lines and equate them. therefore m = 1m > 2m = 1> m = 1/2
So we can conclude that statement1 is sufficient.
Regards, AVR.



Intern
Joined: 11 Oct 2009
Posts: 12

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
07 Jan 2010, 20:23
Thanks guys for your responses. I now see the reasoning behind it... lapse in pretty basic logic.



Manager
Joined: 17 Aug 2009
Posts: 226

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
14 Jan 2010, 12:36
Hi guys
a quick doubt. Isnt the slope of two lines at their intersection points equal?
In that case k=2 at (2,7)



Intern
Joined: 10 Jan 2010
Posts: 10
Schools: wharton, lbs, harvard

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
15 Jan 2010, 01:38
not convincing. the equation for a line needs to be in the "y=mx+c" form for the multiplier of x to be considered as the slope. whats your take on it?



Manager
Joined: 25 Aug 2009
Posts: 168
Location: Streamwood IL
Schools: Kellogg(Evening),Booth (Evening)
WE 1: 5 Years

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
15 Jan 2010, 09:14
1
This post received KUDOS
I agree, statement 2 gives us the value of 2 variables but we have y=mx+b, for which we need the value of The equation of the line y = 2x + 3 gives us no new information apart from the fact that the slope !=2. A is the right choice.
_________________
Rock On



Manager
Joined: 27 Aug 2009
Posts: 137

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
15 Jan 2010, 15:18
I agree too statement B is enough. is the OA different?



Current Student
Joined: 15 Dec 2009
Posts: 289
Schools: Duke

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
15 Jan 2010, 20:23
zaarathelab wrote: Hi guys
a quick doubt. Isnt the slope of two lines at their intersection points equal?
In that case k=2 at (2,7) Answer is A. To my knowledge the slope of two intersecting (straight) lines is never equal. Now for every higher power function it can be the case.
_________________
GMAT Club Premium Membership  big benefits and savings



GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16014

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
13 Feb 2016, 21:10
Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up  doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources



Current Student
Joined: 13 Feb 2011
Posts: 104

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
13 Feb 2016, 21:26
zaarathelab wrote: Hi guys
a quick doubt. Isnt the slope of two lines at their intersection points equal?
In that case k=2 at (2,7) Although this is a pretty old thread/post, I wondered the same question and therefore sharing what I understood after researching a bit. Slope is constant for a line but always between at least two points. Therefore in case of intersection, although the intersection point is same, the steepness (rise/run) for each line defines its slope, and hence it cannot be calculated using just one point.



Math Forum Moderator
Joined: 20 Mar 2014
Posts: 2645
Concentration: Finance, Strategy
GPA: 3.7
WE: Engineering (Aerospace and Defense)

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
13 Feb 2016, 21:32
Dienekes wrote: zaarathelab wrote: Hi guys
a quick doubt. Isnt the slope of two lines at their intersection points equal?
In that case k=2 at (2,7) Although this is a pretty old thread/post, I wondered the same question and therefore sharing what I understood after researching a bit. Slope is constant for a line but always between at least two points. Therefore in case of intersection, although the intersection point is same, the steepness (rise/run) for each line defines its slope, and hence it cannot be calculated using just one point. Slope is a fixed angle value between any two points. As such it is not defined for 1 point as you will end up getting Slope = vertical distance / horizontal distance = 0/0 Thus it does not make any sense to talk about slope of a single point.
_________________
Thursday with Ron updated list as of July 1st, 2015: http://gmatclub.com/forum/consolidatedthursdaywithronlistforallthesections201006.html#p1544515 Rules for Posting in Quant Forums: http://gmatclub.com/forum/rulesforpostingpleasereadthisbeforeposting133935.html Writing Mathematical Formulae in your posts: http://gmatclub.com/forum/rulesforpostingpleasereadthisbeforeposting133935.html#p1096628 GMATCLUB Math Book: http://gmatclub.com/forum/gmatmathbookindownloadablepdfformat130609.html Everything Related to Inequalities: http://gmatclub.com/forum/inequalitiesmadeeasy206653.html#p1582891 Inequalities tips: http://gmatclub.com/forum/inequalitiestipsandhints175001.html Debrief, 650 to 750: http://gmatclub.com/forum/650to750a10monthjourneytothescore203190.html



GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16014

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
22 May 2017, 21:40
Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up  doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources



Manager
Joined: 27 Aug 2014
Posts: 51
Location: Canada
Concentration: Strategy, Technology
GPA: 3.66
WE: Consulting (Consulting)

Re: If Line k in the xyplane has equation y = mx + b, where m and b are [#permalink]
Show Tags
28 May 2017, 11:53
If statement 2 had said perpendicularly intersects  then the answer would have been D. Correct?




Re: If Line k in the xyplane has equation y = mx + b, where m and b are
[#permalink]
28 May 2017, 11:53







