_{n}P_{k}  = 
n!
(n  k)!

Calculator (fill both fields and click 'Calculate'):
Total number of items:n =
How many to choose:k =
Number of permutations:
In scientific notation:
P_{k}(n)  =  n^{k} 
Calculator (fill both fields and click 'Calculate'):
Total number of items:n =
How many to choose:k =
Number of permutations:
In scientific notation:
_{n}C_{k}  = 
n!
k!(n  k)!

=  ( 
n
k

) 
Calculator (fill both fields and click 'Calculate'):
Total number of items:n =
How many to choose:k =
Number of combinations:
In scientific notation:
C_{r}(n, k)  = 
(k + n  1)!
k!(n  1)!

Calculator (fill both fields and click 'Calculate'):
Total number of items:n =
How many to choose:k =
Number of combinations:
In scientific notation: