radhika88 wrote:Hello friends,
Need your help with this DS problem.
Line L passes through points R (0, -5 ) and S (4,0)(see figure below). Point P with coordinates (x, y) is a point on Line L Is xy > 0?
(1) x > 4
(2) y > - 5
Many thanks in advance!
Target question:
Is xy > 0?
Given: Point P with coordinates (x, y) is on Line L
Statement 1: x > 4
If point P is on Line L AND x > 4, then point P can be anywhere on the portion of the line (shown below in red)
Notice that, for
any point on the red part of the line, the x- and y-coordinates will both be positive.
So, it
must be the case that
xy > 0
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: y > - 5
So, point P can be anywhere on the red line (shown below)
There are many points that meet this condition. Here are two:
Case a: point P is here:
In this case, the x-coordinate of P is positive and the y-coordinate is negative, which means
xy < 0
Case b: point P is here:
In this case, the x-coordinate of P is positive and the y-coordinate is positive, which means
xy > 0
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer =
A
Cheers,
Brent
