An email login system uses six-character passwords, and each character is one of the 26 letters (a–z) or the 10 digits (0–9)

An email login system uses six-character passwords, and each character is one of the 26 letters (a–z) or the 10 digits (0–9). Uppercase letters are not used.

(a) Suppose a hacker selects a password at random. What is the probability that your password is selected?

(b) Suppose a hacker knows your password contains only letters and selects a set of six letters at random. What is the probability that your password is selected?

(c) Suppose a hacker has seen you type in the first and last characters in your password. What is the probability that she will get the other four characters correct?