‘n Houer bevat 25 onderdele waarvan drie defektief en 22 nie-defektief is. Indien twee onderdele ewekansig en sonder terugplasing gekies word, is die waarskynlikheid dat slegs een defektief is  / A box contains 25 parts, of which three are defective and 22 are non-defective. If two parts are selected without replacement, the probability that exactly one part is defective, is