The number of distinct subsets of size k from a set of size n is tbinom nk or n choose k.

Sex and drugs are discussed openly (one newspaper recently examined puberty by showing photographs of the development of both male and female genitalia), and you might overhear a pub chat where Jan tells all details of making whoopee.

All the other groups of employees (foremen, clerks, economists, engineers and top managers) also receive bonusses according to the realized profit of the enterprise.

Criminal indulgencers boast, it is true, of their exploits of love, and gallant achievements.