Data Sufficiency

6) Does line k intersect quadrant II?
a. Slope of k is -1/6
b. Y intercept of k is -6

answer A

a says slope = -1/6.

y=(-1/6)x + c.

6y = -x + 6c

now find where this line intersects x and why axis.

the points are (0,c) and (6c,0)

draw this on the co-ordinate plane and verify... if c>0 then both x and y are positive,. so when u draw a line passing thru points it passes through the II quadrant. Note that it won't pass through III quadrant.

Try the same for c<0. both x and y intercepts are negative. again it will pass through II quadrant and this time it wont pass through I.

So A is sufficient.

May there is an easier way to do it! But this was the best I could try

the slope of a negative line always crosses quadrants 2 and 4. y-intercepts tell you nothing about the slope. mark A and move on...

Any better answers please. I do not know how to point moderators or Instructors to address this problem so if somebody would be kind enough to point it to them or give a better explanation.