Free Combination Calculator
Calculate the number of combinations (unordered selections) when choosing r items from n items.
C(n, r)
120
P(n, r) for comparison720
C(n, r) vs Total Items (n)
How to Calculate Combinations
Formula
C(n, r) = n! / (r! * (n - r)!)
A combination counts the number of ways to choose r items from n distinct items where order does not matter. For example, choosing 3 team members from 10 candidates is a combination problem because the group {A, B, C} is the same regardless of selection order.
Example Calculation
How many ways can you choose a committee of 3 from 10 people?
- 01C(10, 3) = 10! / (3! * 7!)
- 02= (10 * 9 * 8) / (3 * 2 * 1)
- 03= 720 / 6 = 120
- 04Compare with permutations: P(10,3) = 720
Frequently Asked Questions
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