This is the question. A computer has a password composed of 6 characters. The first 2 letters must be small letters, the rest can be either numbers or small letters.
a) How many different passwords are possible?
b) How many passwords are there that have no repeated characters?
Thank you for your desire to help. Unfortunately, I haven't understood it very well because the resources with which we were provided was extremely limited. Nevertheless, I will try to understand it. First, the 26 is the number of characters in the English raised to 2 which is the first two characters which are alphabets. Then you add 26 to 10. 10 is the number of digits. This gives you 36 and you raise this to the power of 4. Then you add the . In other words you do
This is because there are ways for the first 2 characters and for the remaining 4 characters which can either be digits or numbers (26+10)?
This is because there are in total 26 characters and there are 26 ways for the first letter and 25 ways for the second letter then 34 ways for the remaining 4 characters: 10 digits and 24 letters?
Any more explanation is appreciated, and thank you.