Mar 19 08:00 AM PDT  09:00 AM PDT Beat the GMAT with a customized study plan based on your needs! Learn how to create your preparation timeline, what makes a good study plan and which tools you need to use to build the perfect plan. Register today! Mar 20 07:00 AM PDT  09:00 AM PDT Join a FREE 1day workshop and learn how to ace the GMAT while keeping your fulltime job. Limited for the first 99 registrants. Mar 20 09:00 PM EDT  10:00 PM EDT Strategies and techniques for approaching featured GMAT topics. Wednesday, March 20th at 9 PM EDT Mar 23 07:00 AM PDT  09:00 AM PDT Christina scored 760 by having clear (ability) milestones and a trackable plan to achieve the same. Attend this webinar to learn how to build trackable milestones that leverage your strengths to help you get to your target GMAT score.
Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 53698

Question Stats:
52% (01:32) correct 48% (01:54) wrong based on 128 sessions
HideShow timer Statistics



Math Expert
Joined: 02 Sep 2009
Posts: 53698

Re M2017
[#permalink]
Show Tags
16 Sep 2014, 01:08



Intern
Status: student
Affiliations: delhi university
Joined: 20 May 2014
Posts: 12
Concentration: Finance, International Business
WE: Accounting (Accounting)

Bunuel wrote: Official Solution:
To answer this question we must know coefficients in front of \(x\) in the equations of the lines. Statement (1) by itself is insufficient. We do not know coefficients in front of \(x\) in the equations of the lines Statement (2) by itself is insufficient. We do not know coefficients in front of \(x\) in the equations of the lines Statements (1) and (2) combined are sufficient. Either \(K = 1\) and \(B = 0\) or vice versa. In either case, a line with slope 0 intersects a line with slope 1 at a 45degree angle.
Answer: C Hi ! i have a doubt . so, i marked B as according to this formula  " tan(theta) = m1  m2/1 + m1*m2" = taking B and K as the slope of either of the equations  as per Option B the denominator in my formula becomes 0 giving not defined solution ,which is the value of only Tan 90. Kindly correct me if im wrong.



Senior Manager
Joined: 31 Mar 2016
Posts: 383
Location: India
Concentration: Operations, Finance
GPA: 3.8
WE: Operations (Commercial Banking)

Re M2017
[#permalink]
Show Tags
23 Jul 2016, 03:05
I think this is a highquality question and the explanation isn't clear enough, please elaborate. "a line with slope 0 intersects a line with slope 1 at a 45degree angle." . Can you please elaborate on this with some relevant theory as to how to determine the angle with this information?



Math Expert
Joined: 02 Sep 2009
Posts: 53698

Re: M2017
[#permalink]
Show Tags
24 Jul 2016, 02:45



Manager
Joined: 17 Aug 2015
Posts: 94

y= mx+c , where m = tan(@) where @ is angle made with x axis so if we know two angles made by two lines on the xy plane, do we need to know the intercepts of line on y axis?
we say that two lines are perpendicular when m1*m2 =1 where m1 and m2 are slopes of two different lines, example tan30 = 1/root 3 , tan120= root3 = tan60
so angle between two lines = 12030= 90
if BK = m1m2= 0 , means either B IS 0 OR K =0, when one of the slope is 0, it means te line is parallel to x axis, example slope m1 = y2y1/x2x1 , take two points (5, 3) , (7,3) so m= 33/75 = 0 . this line has two points whose cordinates have same y distance from the x axis, means parallel to x axis
same way if line is parallel to y axis slope is infinity
also when slope is 1 , it means y2y1= x2x1= so tan45=1 so angle is 45 so combining 1 and 2 we get two lines one with slope 0 and one with slope 45



Senior Manager
Joined: 08 Jun 2015
Posts: 426
Location: India
GMAT 1: 640 Q48 V29 GMAT 2: 700 Q48 V38
GPA: 3.33

Re: M2017
[#permalink]
Show Tags
05 Oct 2017, 06:04
+1 for option C
_________________
" The few , the fearless "



Manager
Joined: 04 Apr 2015
Posts: 187

Re: M2017
[#permalink]
Show Tags
05 Oct 2017, 06:09
At what angle do lines \(y = Kx + B\) and \(y = Bx + K\) intersect ?
(1) \(B + K = 1\)
(2) \(BK = 0\)
we know tanA = (m1m2)/(1+m1m2) where "A" is the angle between the lines and "M1 and M2" are slopes i) knowing B+ K we cannot find M1M2 or M1M2 :insufficient ii)knowing M1M2 we cannot find M1M2 : insufficient
combining i) and ii) we get KB as 1 or 1 ,as case1: B=0 and K=1 case2: B=1 and K=0 but inverse tan of 1 and 1 will give you a 45 degree between: them so combining is sufficient



Manager
Joined: 21 Jul 2017
Posts: 191
Location: India
Concentration: Social Entrepreneurship, Leadership
GPA: 4
WE: Project Management (Education)

Re: M2017
[#permalink]
Show Tags
11 Oct 2017, 09:48
B + K = 1 => B = 1  K
B*K = 0 => K* ( 1  K) = 0 Hence K = 0 or K = 1 for K = 0 , B = 1 and for K = 1 , B = 0
Let K = 1 and B = 0 line 1: y = Kx + B Here slope , K = 1 . hence the line is 45° to the yaxis line 2: y = Bx + K Here the slope , B = 0 . hence the line is 90° to the yaxis
Therefore the lines intersect at 45°angle. Hence sufficient
K = 0 and B = 1 will also give the same result.



Intern
Joined: 16 Jan 2017
Posts: 6

Re: M2017
[#permalink]
Show Tags
31 Jan 2018, 10:28
Hi Bunuel, before I approached each statement, I tried to simplify the expression, letting both lines interesect, to check if both do intersect at all or are just parallel. Kx+B = Bx+K KxK = BxB K(x1) = B(x1) //divide by x1 K= B ...so the statement tells me that K=B? And each answer choice is not sufficient and E should have been the correct answer choice?



Intern
Joined: 01 Aug 2017
Posts: 6
Location: India
GPA: 4

Re: M2017
[#permalink]
Show Tags
31 Mar 2018, 14:18
hi @bunnel,
I came to the same ans as 45 degrees, but intersection of lines make 45 deg and 135 deg both, so opted for E option, can you clarify why only 45 degree is taken into consideration.



Intern
Joined: 29 Mar 2017
Posts: 19
Location: India

Re: M2017
[#permalink]
Show Tags
31 Mar 2018, 14:47
Kontaxis wrote: Hi Bunuel, before I approached each statement, I tried to simplify the expression, letting both lines interesect, to check if both do intersect at all or are just parallel. Kx+B = Bx+K KxK = BxB K(x1) = B(x1) //divide by x1 K= B ...so the statement tells me that K=B? And each answer choice is not sufficient and E should have been the correct answer choice? Even I approached in he same manner... Bunuel please clarify. Sent from my Moto G (4) using GMAT Club Forum mobile app



Intern
Joined: 07 Apr 2018
Posts: 6

Re: M2017
[#permalink]
Show Tags
20 Apr 2018, 07:31
Puja priya wrote: Kontaxis wrote: Hi
before I approached each statement, I tried to simplify the expression, letting both lines interesect, to check if both do intersect at all or are just parallel.
Kx+B = Bx+K
KxK = BxB K(x1) = B(x1) //divide by x1
K= B ...so the statement tells me that K=B? And each answer choice is not sufficient and E should have been the correct answer choice? Even I approached in he same manner... Sent from my Moto G (4) using me too. does it even make sense to simplify the equations?



Intern
Joined: 02 Feb 2018
Posts: 36

Re: M2017
[#permalink]
Show Tags
12 Nov 2018, 05:21
nitsrj wrote: hi @bunnel,
I came to the same ans as 45 degrees, but intersection of lines make 45 deg and 135 deg both, so opted for E option, can you clarify why only 45 degree is taken into consideration. Good question



Intern
Joined: 10 Jul 2016
Posts: 45

Re: M2017
[#permalink]
Show Tags
21 Feb 2019, 13:51
Bunuel wrote: Senthil7 wrote: I think this is a highquality question and the explanation isn't clear enough, please elaborate. "a line with slope 0 intersects a line with slope 1 at a 45degree angle." . Can you please elaborate on this with some relevant theory as to how to determine the angle with this information? A line with the slope of 0 is horizontal and a line with the slope of 1 is 45 degrees with xaxis, thus with the same 45 degrees with other horizontal lines. Check for more here: http://gmatclub.com/forum/mathcoordina ... 87652.htmlHi Bunuel, Is there a page where you have a compilation of all your quant links combined? Thanks, Sid



Math Expert
Joined: 02 Sep 2009
Posts: 53698

Re: M2017
[#permalink]
Show Tags
21 Feb 2019, 21:56










