Every good mathematician is at least half a philosopher, and every good philosopher is at least half a mathematician. -- Friedrich Ludwig Gottlob Frege
According to ETS, the test consists of:
Calculus -- 50%
Material learned in the usual sequence of elementary calculus courses -- differential and integral calculus of one and several variables -- includes calculus-based applications and connections with coordinate geometry, trigonometry, differential equations, and other branches of mathematics
Algebra -- 25%
Elementary algebra: basic algebraic techniques and manipulations acquired in high school and used throughout mathematics
Linear Algebra: matrix algebra, systems of linear equations, vector spaces, linear transformations, characteristic polynomials, and eigenvalues and eigenvectors
Abstract algebra and number theory: elementary topics from group theory, theory of rings and modules, field theory, and number theory
Additional Topics -- 25%
Introductory Real Analysis: sequences and series of numbers and functions, continuity, differentiability and integrability, and elementary topology of R and Rn
Discrete mathematics: logic, set theory, combinatorics, graph theory, and algorithms
Other topics: general topology, geometry, complex variables, probability and statistics, and numerical analysis