  Let X=Sl(3,Z)\Sl(3,R)/SO(3,R). Let N(lambda) denote the dimension of the
space of cusp forms with Laplace eigenvalue less than lambda. We prove that
N(lambda)=C lambda^(5/2)+O(lambda^2) where C is the appropriate constant
establishing Weyl's law with a good error term for the noncompact space X. The
proof uses the Selberg trace formula in a form that is modified from the work
of Wallace and also draws on results of Stade and Wallace and techniques of
Huntley and Tepper. We also, in the course of the proof, give an upper bound on
the number of cusp forms that can violate the Ramanujan conjecture.
