GMAT Math

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

1. The slope of the line L is 3 times y-intercept.
2. The x-intercept of line L is -1/3

The first clue is insufficient. You could intercept the y axis at any point and the slope would then vary.

The second clue is insufficient. you only have one point, there are an infinite number of slopes.


Put them together using the definition of slope: change in y over change in x.

let y = the y intercept, you now have two points: (0,y) the y intercept and (-1/3,0) the x intercept. You can determine the slope
(y-0)/[0- (1/3)] = the slope simplifies to 3y.

but you are told that the intercept is 3y. SO 3y= 3y - you still don't know what y is.