配对问题中的数学期望与方差的直接求法

On direct methods to the mathematical expectation and variance in the matching problem

配对问题中的数学期望与方差的通常求法是引进新的随机变量,本文通过确定随机变量的分布律,直接求解。

The common method to the mathematical expectation and variance in the matching problem is to set new random variables. In this paper, we have given a direct method to the mathematical expectation and variance by determining distribution law of random variables.