12.1.3 Counting permutations
The
perm
or
nPr
command counts permutations.
perm
takes two arguments:
n
and
p
, integers.
perm(
n
,
p
)
returns
P
n
p
, the number of permutations of
n
objects taken
p
at a time.
Example
perm
(5,2)
20