Data Sufficiency

sanaa.rizwan wrote:In the xy coordinate plane, is point R equidistant from points (-3,-3) and (1,-3)?

1. the x coordinate of point R is -1
2. point R lies on the line y = -3

While solving coordinate geometry problems, specifically DS problems, try to draw the scenario and solve by visualizing possible situations.

In this case, if you read the problem carefully or draw the given points on the coordinate plane, you'll notice that y-coordinates of the points are same. Now, the midpoint of the points is ((-3 + 1)/2, (-3 + -3)/2) = (-1, -3)

As the line segment joining the given two points is horizontal, all the points equidistant from these two points will lie on the vertical line passing through (-1, -3). In other words, all the points equidistant from these two points will have x-coordinate = -1 and y-coordinate will vary.

So, the question reduces to "In the xy coordinate plane, is the x-coordinate of the point R equal to -1?"

Now, we can clearly see statement 1 is sufficient but statement 2 is not.

The correct answer is A.