If there are n coins in a bag, of any individual values but of total value P, and if m are drawn at random, without replacement, it may be proved that the mathematical expectation, or probable value, of the draw is mP/n. It must be well known, though I cannot find any reference in the texts, that the same result holds if the coins are replaced after each drawing, or indeed if replacements after certain specified drawings, but not after others, are permitted.