In mathematics you don't understand things, you just get used to them.

DescriptionLink.包里有无穷多个巧克力,巧克力有 $c$ 种颜色,每次从包里拿出不同颜色巧克力的概率都是相等的,桌面的巧克力不允许颜色相同,若某次拿出的巧克力与桌上的巧克力颜色相同...