If repetition is permitted, then 216. Otherwise 120.
There are 60480 numbers.
125
3
ten factorial = 10! = 3,628,800
There are 900 of them.
5040 numbers can be made.
24 different numbers.
27 if the digits can be repeated. 6 if not.
27
6, if you don't repeat any numbers.
24 of them.
1