Part 1: Statement of problems — Combinatorial identities — The principle of inclusion and exclusion: inversion formulas — Stirling, Bell, Fibonacci, and Catalan numbers — Problems in combinatorial set theory — Partitions of integers — Trees — Parity — Connectedness — Extremal problems for graphs and networks — Coloring problems — Hamiltonian problems — Permutations — The number of classes of configurations relative to a group of permutations — Problems of Ramsey type — Part 2: Solutions