There are an infinite number of possibilities based on the infinite set of numbers.
However, for a finite set, there are limited possible combinations, depending on whether you can use the same numbers over again, or if they have to be distinct, or if their order makes any difference.
Here's an example:
For a group of THREE numbers, there is only one possible group of 3 numbers, and there are three possible groups of 2 numbers (i.e. 12, 13, 23) .
Using each of three different numbers, there are 6 ordered combinations of two numbers (12, 13, 23, 21, 31, 32) and 6 possible combinations of three numbers (123, 132, 213, 231, 312, 321).
If the numbers are allowed to repeat, there are 9 possible combinations of two (add 11, 22, 33) and 8 more possible combinations of three (111, 112, 113, 122, 133, 222, 223, 333) - if order matters, each triple (111) has only one possible order, each double has three (112, 121, 211).
The number rapidly increases for larger numbers of possible and larger groups from those sets. The possibilities are called combinations and permutations, and are connected to the numerical property called "factorials" (a number multiplied by all smaller integers - 2 factorial is represented by "2!" and equals 2 x 1 = 2, while 3! = 3 x 2 x 1 = 6). The number of discrete sets of K numbers from N possible numbers is N! / K! x (N-K)!
12
5! = 5x4x3x2x1 = 120
24, none of which are other actual words.
There are 24 different arrangements of 4 numbers (4 factorial or 4!). If you allow numbers to be repeated then the figure becomes 256 (44)
10,000
64 different arrangements are possible.
6*5*4*3*2*1 = 720
12
5! = 5x4x3x2x1 = 120
Five
24, none of which are other actual words.
There are 24 different arrangements of 4 numbers (4 factorial or 4!). If you allow numbers to be repeated then the figure becomes 256 (44)
there are 1,929,770,126,028,800 different colour combinations possible on a Rubik cube.
213 = 8192
10*9*8 = 720
Just 1.
There are two possible arrangements for two methyl groups with respect to a rigid double bond: cis (on the same side) and trans (on opposite sides).