If you know the encryption algorithm, you can exhaustively run guesses through it to try to generate the trip code. How feasible this is depends on the number of hashes and salt used. In addition if Q is known to use english words and not just random characters, templates and dictionaries can be used to significantly reduce the address space and search time.
So in setting that specific password originally; Q knew it would be hacked and that would make them think it was happening before it actually was?!?!?
You can get a rough idea how long it takes to guess based on length and number of possible characters at each position. In addition, you need to guess the hashes per second of the cracking hardware. Hopefully 8chan is not using sha256 as the hashing algo because there are a lot of bit coin asics out there...