
Counting passwords
How many eightcharacter passwords are there if each character is either an uppercase letter AZ, a lowercase letter az, or a digit 09, and where at least one character and at least one number are used?
Total number of passwords possible = $\displaystyle 62^8$
then $\displaystyle 10^8$ of these are all numbers and $\displaystyle 52^8$ are all letters.
So the answer would be $\displaystyle 62^8$  $\displaystyle 10^8$  $\displaystyle 52^8$.
Correct?

Congratulations my friend, you have really come a long way.
Yes indeed that is correct.
Keep up that good work.