GMATPrep DS - 10

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GMATPrep DS - 10

by camitava » Wed May 14, 2008 7:57 am
Require explanation for why not D but A? Obviously OA is A. The question is -

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Correct me If I am wrong


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Amitava
Source: — Data Sufficiency |

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Re: GMATPrep DS - 10

by gabriel » Wed May 14, 2008 10:07 am
camitava wrote:Require explanation for why not D but A? Obviously OA is A. The question is -

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The second statement says nothing about the x intercept of the line nor does it say anything about the slope. Along with the y intercept you need atleast one of the above information to decide in which quadrant the line will fall in. Hence the answer is A.

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by camitava » Wed May 14, 2008 8:27 pm
The second statement says nothing about the x intercept of the line nor does it say anything about the slope. Along with the y intercept you need atleast one of the above information to decide in which quadrant the line will fall in. Hence the answer is A.
Gabriel, the question is asking for the fact whether the line intersects quadrant -II. Now to intersect quadrant-II, the line should pass thru origin. But the line is having -6 as its Y-intercept. So we can say that the line is not passing thru origin. Hence the line is not intercepting the quadrant - II.

Hey Gabriel, am I missing something here?
Correct me If I am wrong


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Amitava

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by wawatan » Thu May 22, 2008 9:32 pm
basically an intercept with a -6 can intersect the quadrant II section with a negative slope. however it can also have a positive slope with the intercept of -6 and will not intersect the quandrant II. therefore the statement is insufficient.

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Properties of slopes

by rdadbhawala » Thu May 22, 2008 10:45 pm
Except for Slope = 0 (x axis or parallel) OR undefined (y axis or parallel), we can say that a positive slope always passes through quadrants I & III, a negative slope will always pass through quadrants II and IV. Passing through the other quadrants is not guaranteed.

The second statement is insufficient as just knowing the intercept guarantees that the quadrants III and IV are intersected, but not quadrant I or II unless we know some other info like slope or x intercept.

- RD