Question 746454
Note that permutation is another word for arrangement. A combination is an arrangement where order does not matter, but for a permutation it does. For example

for combinations

{a,b,c}={a,c,b}={c,b,a}=...

because they all contain an a, b and a c

but if their order is important then all of those lists are distinct arrangements
in fact there are six such arrangements of a,b,c:


abc
acd
bac
bca
cab
cba


hope this helps


:)