Interesting.
Social Security numbers all have the form: (3 digits) - (2 digits) - (4 digits).
That's 9 digits altogether. If you ignore the dashes, you get: xxx,xxx,xxx .
With 9 places, there are 1 billion possible different numbers.
There are 9 digits in a Social Security Number.
There are infinitely many numbers and so infinitely many possible combinations.
There are 5,461,512 such combinations.
2 to the 7th power = 128 * * * * * No. That is the total number of combinations, consisting of any number of elements. The number of 2 number combinations is 7*6/2 = 21
36
If repeats are allowed than an infinite number of combinations is possible.
35
You can make 5 combinations of 1 number, 10 combinations of 2 numbers, 10 combinations of 3 numbers, 5 combinations of 4 numbers, and 1 combinations of 5 number. 31 in all.
The number of combinations is 10C4 = 10*9*8*7/(4*3*2*1) = 210
There are 24C12 = 24!/[12!*12!] = 2,704,156 combinations.
There are 12,033,222,880 of them.
Just 4: 123, 124, 134 and 234. The order of the numbers does not matter with combinations. If it does, then they are permutations, not combinations.
Assuming a number can appear only once, there are 47C5 = 47*46*45*44*43/(5*4*3*2*1) = 1,533,939 combinations.
There are 7C4 = 7!/(4!*3!) = 7*6*5/(3*2*1) = 35 combinations.
The number of combinations is 20C5 = 20!/(15!*5!) = 20*19*18*17*16/(5*4*3*2*1) = 15,504
last 4 digits of your social secutrity number
None, unless you are considering the number of people whose surnames are Condon.