免费组合计算器
计算组合数C(n,r)，确定无序选取方案的总数。
Combinations
120
Permutations720
公式
## How to Calculate Combinations ### Formula **C(n, r) = n! / (r! × (n - r)!)** Where: - **n** = total number of items - **r** = number of items being chosen Combinations count selections where **order does not matter**.
计算示例
How many ways can you choose 3 items from a set of 10? (Order does not matter)
- 01C(10, 3) = 10! / (3! × 7!)
- 02= 3,628,800 / (6 × 5,040)
- 03= 3,628,800 / 30,240
- 04= 120
常见问题
What is a combination?
A combination is a selection of objects where the order does not matter. Choosing {A, B, C} is the same as choosing {C, B, A}.
Where are combinations used?
Combinations are used in lottery calculations, committee selections, card hands (e.g., poker), and any scenario where you select items without regard to order.
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