Counting Flashcards
1
Q
Ordered choice with repetitions
A
n^k
2
Q
Ordered choice without repetitions
A
n! / (n-k)!
3
Q
Unordered choice without repetitions
A
n! / k!(n-k)! = (n choose k)
4
Q
Unordered choice with repetitions
A
(k+n-1) choose (n-1)
5
Q
what does n stand for
A
n options / number of choices
6
Q
what does k stand for
A
how many we want / number of spots to fill / how many we are working with
7
Q
How to calculate n choose k
A
n! / k!(n-k)!