lines lines and more lines

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lines lines and more lines

by divya23 » Wed Jun 01, 2011 9:59 pm
Lines n and p lie in the xy plane.Is the slope of line n < slope of line p ?
1.lines n and p intersect at he point (5,1)
2.The y intercept of line n > y int of line p.

[spoiler]OA = Both[/spoiler]
Source: — Data Sufficiency |

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by cans » Wed Jun 01, 2011 10:32 pm
a) insufficient. no information given about slope
b) y-intercept doesn't determine slope. insufficient
a&b) insufficient.
IMO E

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by Anurag@Gurome » Wed Jun 01, 2011 10:44 pm
divya23 wrote:Lines n and p lie in the xy plane.Is the slope of line n < slope of line p ?
1.lines n and p intersect at he point (5,1)
2.The y intercept of line n > y int of line p.

[spoiler]OA = Both[/spoiler]

Solution:
Let the equation of line n be y = m1x+c1 and let the equation of line p be y = m2x+c2.
We need to know whether m1 < m2 or not.
Let us first consider (1)alone.
So, 1 = 5*m1 + c1 and 1 = 5*m2 + c2.
From this we cannot say whether m1 < m2 or not.
Next, consider (2) alone.
It means that c1 > c2..
Again, from this we cannot say whether m1 < m2 or not.
Lastly, combine both statements together and check.
We get that 1-5m1 > 1-5m2,
Or m1 < m2.

The correct answer is (C).
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
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