Combinations Formula
也称为: nCr Formula, Binomial Coefficient
C(n, r) = \binom{n}{r} = \frac{n!}{r!(n-r)!}
C(n,r) = n! / (r!(n-r)!)它计算什么
Counts the number of ways to choose r items from n, where ORDER DOES NOT MATTER.
变量
| 象征 | 姓名 | 描述 |
|---|---|---|
| n | Total Items | Total number of items |
| r | Items Chosen | Number of items selected |
工作示例
1
C(10,3) = 10! / (3! × 7!)2
= (10×9×8) / (3×2×1) = 720/6 = 120结果: 120
尝试计算器
相关公式
#combinatorics#probability#counting