GMAT PREP question

priyankamishra11 wrote:Please explain why 2nd stmt. is not sufficient?

(2) the y intercept of k is -6

Well, if the equation of line k is y=-6, then k will not intersect sector II.

If the equation of line k is y = -(1/6)x - 6, then k will intersect sector II.

So, the answer could be "no" or "yes": insufficient.

Here's the general rule on which you're being tested:

A line with a negative slope will ALWAYS intersect sectors II and IV. (It will also pass through one of the other sectors, unless it passes through the origin.)

A line with a positive slope will ALWAYS intersect sectors I and III. (It will also pass through one of the other sectors, unless it passes through the origin.)

Stuart Kovinsky wrote:

priyankamishra11 wrote:Please explain why 2nd stmt. is not sufficient?

(2) the y intercept of k is -6

Well, if the equation of line k is y=-6, then k will not intersect sector II.

If the equation of line k is y = -(1/6)x - 6, then k will intersect sector II.

So, the answer could be "no" or "yes": insufficient.

Here's the general rule on which you're being tested:

A line with a negative slope will ALWAYS intersect sectors II and IV. (It will also pass through one of the other sectors, unless it passes through the origin.)

A line with a positive slope will ALWAYS intersect sectors I and III. (It will also pass through one of the other sectors, unless it passes through the origin.)

Hi Stuart,

Can you pls. elaborate :
If the equation of line k is y = -(1/6)x - 6, then k will intersect sector II.
So, the answer could be "no" or "yes": insufficient.
How did u get this equaltion from statement 2 alone?

Thanks

anju wrote:

Stuart Kovinsky wrote:

priyankamishra11 wrote:Please explain why 2nd stmt. is not sufficient?

(2) the y intercept of k is -6

Well, if the equation of line k is y=-6, then k will not intersect sector II.

If the equation of line k is y = -(1/6)x - 6, then k will intersect sector II.

So, the answer could be "no" or "yes": insufficient.

Here's the general rule on which you're being tested:

A line with a negative slope will ALWAYS intersect sectors II and IV. (It will also pass through one of the other sectors, unless it passes through the origin.)

A line with a positive slope will ALWAYS intersect sectors I and III. (It will also pass through one of the other sectors, unless it passes through the origin.)

Hi Stuart,

Can you pls. elaborate :
If the equation of line k is y = -(1/6)x - 6, then k will intersect sector II.
So, the answer could be "no" or "yes": insufficient.
How did u get this equaltion from statement 2 alone?

Thanks

All we know from statement (2) is that the y intercept is -6.

When we pick numbers in data sufficient yes/no questions, our goal is to get both a "yes" answer AND a "no" answer. So, I just picked a line (that satisfied the condition in the rule, i.e. y-int of -6) with a slope that would generate a "yes" answer.