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line n and p lie in the xy plane, is the slope of line n [#permalink]
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06 Jan 2008, 09:13
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line n and p lie in the xy plane, is the slope of line n less than the slope of line p? (1) n and p intersects at point (5;1) (2)yintercept of line n is greater than yintercept of line p
if possible, pls with explanation... OA is C



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Re: GMATPrep [#permalink]
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06 Jan 2008, 09:33
kazakhb wrote: line n and p lie in the xy plane, is the slope of line n less than the slope of line p? (1) n and p intersects at point (5;1) (2)yintercept of line n is greater than yintercept of line p
if possible, pls with explanation... OA is C Slope is (Y2Y1)/(X2X1) 1: No help here at all. 2: No help again. Together: lets just pick a random point. (0,3) and (0,4) p and n respectively. (41)/(05) (31)/)(05) > 3/5 < 2/5 (03) (0,4) n and p respectively (31)/(05) and (41)/(05) > 4/5 < 1 So suff.



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Re: GMATPrep [#permalink]
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08 Jan 2008, 20:14
GMATBLACKBELT wrote: kazakhb wrote: line n and p lie in the xy plane, is the slope of line n less than the slope of line p? (1) n and p intersects at point (5;1) (2)yintercept of line n is greater than yintercept of line p
if possible, pls with explanation... OA is C Slope is (Y2Y1)/(X2X1) 1: No help here at all. 2: No help again. Together: lets just pick a random point. (0,3) and (0,4) p and n respectively. (41)/(05) (31)/)(05) > 3/5 < 2/5 (03) (0,4) n and p respectively (31)/(05) and (41)/(05) > 4/5 < 1 So suff. Dont follow your approach here, can you explain ?



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Re: GMATPrep [#permalink]
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08 Jan 2008, 20:57
Let the lines be y = Nx +c1, y = Px + c2 where N and P are the slopes of lines n and p
from 1) Each of them passes thru (5,1)
1 = 5N + c1, 1 = 5P+c2 => c1 = 1  5N, c2 = 1  5P....Not sufficient
from 2) c1 > c2 ...Not suffficient
Combining 1) & 2) 15N>15P
=> P > N....Hence C



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Re: GMATPrep [#permalink]
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09 Jan 2008, 02:05
kazakhb wrote: line n and p lie in the xy plane, is the slope of line n less than the slope of line p? (1) n and p intersects at point (5;1) (2)yintercept of line n is greater than yintercept of line p
if possible, pls with explanation... OA is C Stat 1: n could be  to x axis with slope 0 and p could be downward sloping, i.e., w/ slope ve. Answer to step is no. p could be  to x axis w/ slope 0 and n could be downward sloping, i.e., w/ ve slope. Answer to stem is yes. Insuff. Stat 2: n could intercept y axis at 5 and be  to p which intercepts the y axis at 2, in which case slopes are equal. n could be downward sloping intersecting y axis at 5 and p could be upward sloping intersecting the y axis at 2. Insuff. Together: If n and p intersects at point (5,1) & yintercept of line n is greater than yintercept of line p then slope of n has to be less than slope of p. Suff.



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Re: GMATPrep [#permalink]
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09 Jan 2008, 02:23
sam76 wrote: Let the lines be y = Nx +c1, y = Px + c2 where N and P are the slopes of lines n and p
from 1) Each of them passes thru (5,1)
1 = 5N + c1, 1 = 5P+c2 => c1 = 1  5N, c2 = 1  5P....Not sufficient
from 2) c1 > c2 ...Not suffficient
Combining 1) & 2) 15N>15P
=> P > N....Hence C I like this, thanks
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Re: GMATPrep [#permalink]
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09 Jan 2008, 02:41
sam76 wrote: Let the lines be y = Nx +c1, y = Px + c2 where N and P are the slopes of lines n and p
from 1) Each of them passes thru (5,1)
1 = 5N + c1, 1 = 5P+c2 => c1 = 1  5N, c2 = 1  5P....Not sufficient
from 2) c1 > c2 ...Not suffficient
Combining 1) & 2) 15N>15P
=> P > N....Hence C thanks very detailed



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Re: GMATPrep [#permalink]
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09 Jan 2008, 13:10
GK_Gmat wrote: kazakhb wrote: line n and p lie in the xy plane, is the slope of line n less than the slope of line p? (1) n and p intersects at point (5;1) (2)yintercept of line n is greater than yintercept of line p
if possible, pls with explanation... OA is C Stat 1: n could be  to x axis with slope 0 and p could be downward sloping, i.e., w/ slope ve. Answer to step is no. p could be  to x axis w/ slope 0 and n could be downward sloping, i.e., w/ ve slope. Answer to stem is yes. Insuff. Stat 2: n could intercept y axis at 5 and be  to p which intercepts the y axis at 2, in which case slopes are equal. n could be downward sloping intersecting y axis at 5 and p could be upward sloping intersecting the y axis at 2. Insuff. Together: If n and p intersects at point (5,1) & yintercept of line n is greater than yintercept of line p then slope of n has to be less than slope of p. Suff. Guys, this is a correct answer of course but in my opinion it takes too much time to solve it algebrally. (1) I would draw the xy plain, put the (5,1) point on it and draw 2 straight lines. they can be drawn all over the plain.insuff (2) again, on the same xy plain I draw two points intersecting the y axis, (n,0) point is higher than (p,0) point. insuff. draw 2 stright lines from (n,o) to (5,1) and from (p,0) to (5,1) and see that the the lines can not be drawn diffrently. slope has to be different.suff took me less than a minute. I think that in this case it works better for me



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Re: GMATPrep [#permalink]
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09 Jan 2008, 20:23
kazakhb wrote: line n and p lie in the xy plane, is the slope of line n less than the slope of line p? (1) n and p intersects at point (5;1) (2)yintercept of line n is greater than yintercept of line p
if possible, pls with explanation... OA is C 1) We know the intersection point, but we don't know anything else  INSUFFICIENT 2) We know the yintercepts, but this doesn't tell us anything about the slope TOGETHER Since the yintercept of n is greater than p, we know that n's slope must be less than p, otherwise they wouldn't intersect.










