Monday, May 4, 2009

Problem 25 - GMAT Coordinate Geometry

In a rectangular coordinate system, if a and b are positive integers, is point (a, b) above line y = x?

(1) a = 4

(2) b = a + 2


  1. It is B.

    (2) b is not equal to a, so it doesn't lie on y = x

  2. Lying above x=y means y>=x must be true. Therefore, B is sufficient as it satisfies the condition for all positive values of x and y.