9. A secretary was given n computer passwords and tries the passwords at random. Exactly one password will permit access to a computer file. Suppose now that the secretary selects a password, tries...

9. A secretary was given n computer passwords and tries the passwords at random. Exactly one
password will permit access to a computer file. Suppose now that the secretary selects a password,
tries it, and – if it does not work – puts it back in with the other passwords before randomly
selecting the next password to try (not a very clever secretary!). What is the probability that the
correct password is found on the sixth try?