1000
10,000
15
575757
Through the magic of perms and coms the answer is 729
There are a huge number of combinations of 5 numbers when using the numbers 0 through 10. There are 10 to the 5th power combinations of these numbers.
To calculate the number of different 4-digit combinations that can be made using numbers 0 through 9, we use the concept of permutations. Since repetition is allowed, we use the formula for permutations with repetition, which is n^r, where n is the number of options for each digit (10 in this case) and r is the number of digits (4 in this case). Therefore, the number of different 4-digit combinations that can be made using numbers 0 through 9 is 10^4, which equals 10,000 combinations.
There are 360 of them.
0000 0001 0002 ... 9998 9999
Their is 25 combinations
Number of 7 digit combinations out of the 10 one-digit numbers = 120.
There is only one combination. In a combination the order of the numbers does not matter so the only combination is 0123456789. This is the same as 1326458097