Quadrant of the coordinate plane(Knewton Prep)

[RadiumBall]

In which quadrant of the coordinate plane does point (w, z) lie, if wz ≠ 0?

1.(z, w) is in quadrant III.
2.(-w, z) is in quadrant IV

[vineeshp]

From 1,
we can find the signs of z,w.

From 2 too, we can find the signs of z,w.

Hence D. Either statement is sufficient.

[Anurag@Gurome]

In which quadrant of the coordinate plane does point (w, z) lie, if wz ≠ 0?

1.(z, w) is in quadrant III.
2.(-w, z) is in quadrant IV

Solution:
Let us first consider (1) alone.
It says (z,w) is in quadrant III.
So, both z and w are negative, for example (-2,-3), z = -2 and w = -3.
Now, (w,z) is (-3,-2) which again lies in the third quadrant.
Or, statement (1) alone is sufficient to answer the question.
Next, consider statement (2) alone.
It says (-w,z) is in quadrant IV.
So, -w is positive and z is negative.
This also means that w is negative.
Or (w,z) lies in the third quadrant.
Hence, even statement (2) alone is sufficient to answer the question.

The correct answer is (D).

[RadiumBall]

Thanks for the explanation Anurag. I get it now...

[Anurag@Gurome]

Thanks for the explanation Anurag. I get it now...

You are welcome.