Includes bibliographies.

On the question of "how many": Definition of the notion of cardinality of finite sets in some arithmetical systems /; Application of Hausdorff dimension in the theory of Diophantine approximations /; On the irrationality of some quantities containing zeta (3) /; Characteristic roots of stochastic matrices /; On the characteristic roots of matrices with nonnegative elements /; Finite basis property for the identities of representations of a simple three-dimensional Lie algebra over a field of characteristic zero /; On the number of nontrivial solutions of homogeneous equations in words with three unknowns /; On the representation of monoids by multivalued mappings /; Representation of functions in convex domains by generalized exponential series /; Remarks on algebraic supermanifolds /; On some connections between vector optimization and geometric optimization and their economic applications / D. P. Skvortsov; V. I. Bernik; L. A. Gutnik; N. A. Dmitriev and E. B. Dynkin; F. I. Karpelevich; Yu. P. Razmyslov; L. G. Kiseleva; L. A. Skornyakov; A. F. Leontev; Yu. I. Manin; K.-H. Elster and R. Heine