If you can repeat a digit, there are 27. If you can't repeat a digit, there are only 6.
24 if you don't repeat any numbers.24
If you can repeat the numbers within the combination there are 10,000 different combinations. If you cannot repeat the numbers within the combination, there are 5040 different combinations.
120 combinations using each digit once per combination. There are 625 combinations if you can repeat the digits.
6, if you don't repeat any numbers.
This question does not make sense since a combination is independent of the order of its elements. That is, the combinations 1245 and 5142 are the same. Consequently, there can be no "last " numbers in a combination.
none
The second digit can be 2,4,6, or 8. There are 4 ways of choosing the second digit. The first digit can be chosen from the remaining 8 digits. 8x4 = 32 numbers. Here, it is assumed that the numbers do not repeat
Six, if you don't repeat any digits.
9999
Six, if you don't repeat any.
6 if you don't repeat any.