Availability of multiprocessor computers, allows us to solve many complex problems using Monte Carlo method. Monte Carlo methods have been further developed to solve a variety of multidimensional integrals, linear and nonlinear boundary value problems. In monograph we used the deep connections between differential equations and random processes. This connection has been known long ago, the results of the theory of differential equations have been widely used in the theory of probability and vice versa. The solutions of large class linear and nonlinear equations of elliptic and parabolic type...