Question

How many passwords are there of length 6 through 8 consisting of uppercase letters and digits , where there is at least one digit?

Answer 1

The easiest way to count the acceptable passwords is to note that there are 36^6 six-character strings made up of upper-case letters and digits, and 26^6 of them are made up entirely of letters, so there are 36^6−26^6 that include at least one digit

Step-by-step explanation: