89,999 different numbers i guess
999 are whole.
Different schemes have different id numbers of different lengths.
There are 41 of them.
The sum of the number of digits in all the numbers between 31 and 400 inclusive is 1041.
There are 6484 digits BETWEEN the two given numbers.
89,999 different numbers i guess
999 are whole.
223
123
The answer will depend on how many digits you have at your disposal. Working with the 10 digits, and barring leading zeros, there are 8,877,690 numbers.
Different schemes have different id numbers of different lengths.
5040 different 4 digit numbers can be formed with the digits 123456789. This is assuming that no digits are repeated with each combination.
There are 41 of them.
The sum of the number of digits in all the numbers between 31 and 400 inclusive is 1041.
If the digits are all different then 18. Otherwise, 192.
I believe here are 51 such numbers.