24 possible combinations:
1234,
1243,
1324,
1342,
1423,
1432,
2134,
2143,
2314,
2341,
2413,
2431,
3124,
3142,
3214,
3241,
3412,
3421,
4123,
4132,
4213,
4231,
4312,
4321
Generalizing it, you can only make n! combinations out of n different digits.
n! = 1 * 2 * 3 * ... * n . (Math definition: the factorial of a positive integer n, denoted by n!, is the product of all positive integers less than or equal to n)
When n = 4 , n! = 1 * 2 * 3 * 4 = 24.
If 16 digits are available, let's say 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F you can make
1 * 2 * 3 * 4 * ... * 16 = 2 ^15 * 3 ^6 * 5 ^3 * 7 ^2 * 11 * 13 = Excuse me, but I am not going to bring the product. Use your calculator (and be prepared for an overflow).
Anyway, it is:
16! = 32768 * 729 * 125 * 49 * 11 * 13 = 32768 * 729 *125 * 7007 = 32768 * 729 * 875875 = whatever... almost 20 trillion combinations of 16 different digits.
1234
A lot. And there is akways the code. 1234
There are 15, and they are:1234 1235 1236 1245 1246 1256 1345 1346 1356 1456 2345 2346 2356 2456 3456.
There are 24 combinations if you use each digit only once per combination: 123 124 132 134 142 143 213 214 231 234 241 243 312 314 321 324 341 342 412 413 421 423 431 and 432.
4 of them. In a combination the order of the numbers does not matter.
24
Twelve of them.
smallest=1234 greatest=4321
With repeats: 4×4 = 16; Without repeats: 4×3 = 12.
4 x 3 x 2 ie 24
4*3*2*1 = 24
1234, 2637, 7777, 2727 are examples of a four digit number. So any random four numbers are four digits.
There are 4^6 = 4096 such numbers.
64 if repetition is allowed.24 if repetition is not allowed.
256
That would be 4! = 4 * 3 * 2 * 1 = 24
1234