Employees at a company are given a three digit employee identification code. If each digit cannot be repeated, how many different codes are possible?

720 codes.

There are 10 digits possible for the first digit of the code.

Since there can be no repeated digits, you subtract 1 and find there are only 9 possible digits for the second digit in the code.

Finally, subtract 1 again to find there are only 8 possible digits for the last digit.

Multiply these together to find the number of combinations.

10 * 9 * 8

90 * 8

720

So, there are 720 combinations if digits cannot be repeated.