There are 27 PERMUTATIONS, but not combinations. The combinations 113 is the same as 131 or 311 etc.
The ten different combinations are:
111, 222, 333,
112, 113, 122, 223, 133, 233,
123
9,000 - all the numbers between 1,000 and 9,999 inclusive. * * * * * NO. Those are PERMUTATIONS, not COMBINATIONS. Also, the question specified 4 digit combinations using 4 digits. The above answer uses 10 digits. If you start with 4 digits, you can make only 1 combination.
All numbers are made with digits and there is no limit on how big they can be. So there is no greatest number.
Well you have 10 possible numbers for the fist column(0-9) and 10 for the second, third, and fourth then you multiply those numbers. 10*10*10*10=10000 or 10^4=10,000. So there are 10,000 different combinations.
6
There are 11,238,513 of them.
45
6
10
32C3 = 4960
Six combinations: 123, 132, 213, 231, 312, 321
Assuming you are treating each number as a number and not as an individual unit, the numbers you can make from these digits are 899, 989 and 998.
9,000 - all the numbers between 1,000 and 9,999 inclusive. * * * * * NO. Those are PERMUTATIONS, not COMBINATIONS. Also, the question specified 4 digit combinations using 4 digits. The above answer uses 10 digits. If you start with 4 digits, you can make only 1 combination.
If the 6 digits can be repeated, there are 1296 different combinations. If you cannot repeat digits in the combination there are 360 different combinations. * * * * * No. That is the number of PERMUTATIONS, not COMBINATIONS. If you have 6 different digits, you can make only 15 4-digit combinations from them.
120 combinations using each digit once per combination. There are 625 combinations if you can repeat the digits.
10,000.
017, 071, 107, 170, 701, 710. 6 combinations
5040, assuming none of the digits are the same. (Assuming they're not, there's 5040 unique combinations you can make out of 7 digits).