GMAT prep coordinate geometry

[awilhelm]

In the xy-plane, what is the y-intercept of line L?

1) The slope of line L is 3 times its y-intercept
2) The x-intercept of line L is -1/3

[gaggleofgirls]

1) gives us the equation: y = 3(C)x + C where C is the constant representing the y intercept. That alone is not enough to actually give the Y intercept, so not sufficient.

2) The x-intercept of line L = -1/3. Only tells us the X intercept, on its own, not sufficient.

So that leaves us C - together sufif or E - togethre not sufficient.

When you put them together you get:
0 = 3(C)(-1/3) + C
0 = -C + C
0 = 0
Still doesn't tell us the slope or the Y intercept, so insufficient.

Answer = E.

-Carrie

[awilhelm]

Right, thanks!

[malhotneha]

[quote="awilhelm"]In the xy-plane, what is the y-intercept of line L?

1) The slope of line L is 3 times its y-intercept
2) The x-intercept of line L is -1/3[/quote]

Whats the QA?