Statistics 简明教程

Statistics - Combination with replacement

由数字或事物的集合可以按多种方式排列或组合的每一种可能方式,称为排列。概率中带放回的组合是从无序列表中多次选择一个对象。

Each of several possible ways in which a set or number of things can be ordered or arranged is called permutation Combination with replacement in probability is selecting an object from an unordered list multiple times.

带放回的组合由以下概率函数定义和给出:

Combination with replacement is defined and given by the following probability function −

Formula

其中——

Where −

  1. ${n}$ = number of items which can be selected.

  2. ${r}$ = number of items which are selected.

  3. ${^nC_r}$ = Unordered list of items or combinations

Example

Problem Statement

Problem Statement

有五种冷冻酸奶:香蕉、巧克力、柠檬、草莓和香草。你可以有三个勺子。有多少种口味可以选?

There are five kinds of frozen yogurt: banana, chocolate, lemon, strawberry and vanilla. You can have three scoops. What number of varieties will there be?

Solution

Solution

此处 n = 5且r = 3。将值代入公式,

Here n = 5 and r = 3. Substitute the values in formula,

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