Passwords on an ancient computer are required to be 4-5characters long and made up of lower case letters only (a..z :there are 26 possibilities). Please answer each of these questionsbelow, giving numerical answers. You should also explain how yougot each answer, for full or partial credit.
a) Assume that letters may NOT be repeated, and passwords are4-5 letters long. How many passwords are possible?
b) Assume that letters MAY be repeated, and passwords are 4-5letters long. How many passwords are possible?
c) Assuming that letters MAY be repeated, what proportion of thetotal number of passwords in fact *do* have at least one letterused more than once?
d) Letters may be repeated but the following extra rulesexist:
- The password cannot be 4 or 5 identical letters like xxxx orbbbbb
- The password cannot be on a list of 71 common 4-5 letter words(none of them are like xxxx or bbbbb!)
How many passwords are possible now?
Note: since this is a practice test question, the answers can beseen in the question comment after you turn in your quiz. Canvascan't grade \"essay\" type questions for correctness, so you will geta 0 grade whatever you write.
