4
216
There are 210 4 digit combinations and 5040 different 4 digit codes.
There are 840 4-digit combinations without repeating any digit in the combinations.
5,040
4
There are 5,040 combinations.
There are 120 permutations and 5 combinations.
216
120 combinations using each digit once per combination. There are 625 combinations if you can repeat the digits.
4582
20
9000
There are 210 4 digit combinations and 5040 different 4 digit codes.
There are 840 4-digit combinations without repeating any digit in the combinations.
10,000
4!=4x3x2x1=24