1. The company has agreed on a 9- character password format, comprised of uppercase letters, lower case letters, and digits (0-9). However, the rules specify that the first 3 characters have to be digits and the next 6 can be any upper case or lower case letter. How many possible passwords are there if: a. repetitions are allowed: b. repetitions are not allowed:

a) 1977060966, b) 146581344.

Step-by-step explanation:

Since we have given that

There are 10 numbers,

There are 26 lower case letters,

There are 26 upper case letters,

Since the first 3 characters have to be digits and next 6 can be upper or lower.

So, a) repetitions are allowed:

b) repetitions are not allowed:

Hence, a) 1977060966, b) 146581344.

answer: your correct answer is b. d.

step-by-step explanation: