11 choose 2
Choosing 2 from 11— order doesn't matter.
Combinations (order doesn't matter)
11C2 = 55
Permutations (order matters): 11P2 = 110
There are 55 ways to choose 2 items from 11when order doesn't matter, using the formula C(n, k) = n! / (k! · (n − k)!).
11 choose k table
| Expression | Combinations |
|---|---|
| 11 choose 0 | 1 |
| 11 choose 1 | 11 |
| 11 choose 2 | 55 |
| 11 choose 3 | 165 |
| 11 choose 4 | 330 |
| 11 choose 5 | 462 |
| 11 choose 6 | 462 |
| 11 choose 7 | 330 |
| 11 choose 8 | 165 |
| 11 choose 9 | 55 |
| 11 choose 10 | 11 |
| 11 choose 11 | 1 |
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Frequently asked questions
What is 11 choose 2?+
11 choose 2 equals 55. It counts the number of ways to choose 2 items from 11 when the order does not matter.
What is the formula for 11 choose 2?+
The combinations formula is C(n, k) = n! / (k! · (n − k)!). For 11 choose 2: 11! / (2! · 9!) = 55.