4!4!4!4!= 331776 with repetition
Or 4!=24 without repetition.
There are 210 4 digit combinations and 5040 different 4 digit codes.
if its not alphanumeric, 999999 variations
There are 5,040 combinations.
Number of 7 digit combinations out of the 10 one-digit numbers = 120.
There are twelve possible solutions using the rule you stated.
It can be calculated as factorial 44! = 4x3x2x1= 60
9
1
Possible 5 digit combinations using 5 digits only 1 time is 5! or 5*4*3*2*1 or 120. Using 5 digits where numbers can be used 5 times is 55 or 3125.
i would like a list all possible 4 digit combination using 0-9
15
10,000