We propose a modified Monte-Carlo method for studying the solvation of ions in a mixed solvent. We include two-particle shifts in the algorithm along with oneparticle shifts. Some of the two-particle shifts end with exchange of adjacent molecules. We have carried out calculations for the system Na⁺-N₁·H₂O-N₂·MeOH for N₁=N₂=6 and N₁=N₂=9. We have concluded that there is preferential hydration of the Na⁺ ion in an equimolar water-methanol mixture.