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s.pratibha14
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Post subject: In the XY-coordinate plane, line L and line K intersect  Posted: Mon Feb 13, 2012 2:35 pm |
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Posts: 9
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plz suggest how to approach this question?
in XY Plane, line K passes through the point(1,a) and L passes through the (1,b) and both the lines passes through the origin point.
Whether K's Slope greater than the L slpoe?
1. ab>0
2.|a| > |b|
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aspirant_gmat_2012
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Post subject: Re: In the XY-coordinate plane, line L and line K intersect Posted: Tue Feb 14, 2012 5:28 am |
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Hi Pratibha,
Is the OA = (C)?
Approach:
Use y=mx+c equation. Since lines pass through (1,a) and (1,b) resply, we have:
1=am1 + C1
1=bm2 + C2
Since the lines also pass through (0,0), C1=0 and C2=0.
Hence, m1= (b/a)m2. Therefore, the question is actually is b>a?
(I) : a and b have same signs, not sufficient.
(II): Absolute values are less, not sufficient.
Combined: Sufficient, when both have same signs and |a| > |b| then b is necessarily greater than a.
Hope it helps,
Syed
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s.pratibha14
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Post subject: Re: In the XY-coordinate plane, line L and line K intersect Posted: Tue Feb 14, 2012 5:39 am |
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Hi Syed,
U have written that
{Use y=mx+c equation. Since lines pass through (1,a) and (1,b) resply, we have:
1=am1 + C1
1=bm2 + C2}
why did u put 1 in place of Y in Y= mX+C
As we know that 1 is x cordinate and a is y cordinate.
Please explain.
and OA is E.
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aspirant_gmat_2012
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Post subject: Re: In the XY-coordinate plane, line L and line K intersect Posted: Tue Feb 14, 2012 5:59 am |
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Yea, my mistake. This explains why you should not solve quant questions at work ;)
Nevertheless, I think you must have got the answer now. Just use a & b as (3,2) & (-3,-2) to prove & disprove.
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s.pratibha14
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Post subject: Re: In the XY-coordinate plane, line L and line K intersect Posted: Tue Feb 14, 2012 6:12 am |
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got it :) why did u get it wrong.
I was just wanted to confirm my approach.. its same as u told...
Thanx for ur effort ...
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aspirant_gmat_2012
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Post subject: Re: In the XY-coordinate plane, line L and line K intersect Posted: Tue Feb 14, 2012 6:17 am |
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I took the points as (a,1) and (b,1).
U r wlcmd,
Syed
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nakul.maheshwari000
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Post subject: Re: In the XY-coordinate plane, line L and line K intersect Posted: Sat Feb 18, 2012 12:46 pm |
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You can also say:
M(k) = a (y2-y1/x2-x1)
M(l) = b
Then just pick numbers.
Option A - ab > 0.
- Does not help here at all. It can be 6.3 > 0 or -6 X -3 > 0
Option B - |a| >|b|
- Does not work either. It can 6 > 3 or |-6| > |-3|
Combine both
Same deal. Both the numbers can be either positive or negative.
Hence Insufficient, Answer - E
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jnelson0612
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Post subject: Re: In the XY-coordinate plane, line L and line K intersect Posted: Sun Feb 19, 2012 10:25 pm |
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| ManhattanGMAT Staff |
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Posts: 2391
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It is always great to see students helping each other! Thanks everyone!
_________________
Jamie Nelson
ManhattanGMAT Instructor
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rohansharmaster
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Post subject: Re: In the XY-coordinate plane, line L and line K intersect Posted: Sat Mar 24, 2012 3:09 pm |
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If I consider both lines to have negative slope using option C then must I assume that a slope of -6 is less than a slope of -3 ?
Although -6<-3 but a slope of -6 is steeper than -3 no ?
I'm confused ..
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tim
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Post subject: Re: In the XY-coordinate plane, line L and line K intersect Posted: Sun Apr 22, 2012 4:53 am |
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| ManhattanGMAT Staff |
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Posts: 4406
Location: Southwest Airlines, seat 21C
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you seem to be purposely misinterpreting the definition of "less"..
_________________
Tim Sanders
Manhattan GMAT Instructor
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