In this regard, how many combinations can you make with numbers 0 9?
10,000 possible combinations
One may also ask, how many possible codes can be formed with a lock that uses 5 numbers from 0 9? Since each digit is used once, you have 10 possible choices (0–9) for the first digit.
Likewise, people ask, how many 4 digit numbers can be formed using the digits 0 9?
For each choice of the first two digits you have 10 choices for the third digit. Thus you have 10x10x10 = 1000 choices for the first three digits. Finally you have 10 choices for the fourth digit and thus there are 10x10x10x10 = 10 000 possible 4 digit combinations from 0-9.
How many numbers can be formed with 5 digits?
There are 6C5 = 6 combinations of the five digits; of those, two (12345 and 01245) will produce multiples of three. There are 5! = 120 orderings for each. So the total is 2 * 120 = 240.
