Might be the least "silly" even if improbable - if you're going to brute force the door and you know how long the code is then this cuts the time down significantly
Impossible, so it's not just silly it's outright stupid
Also impossible, but the brazenness makes it kinda silly
Silly, but a little too real
Extremely silly in a funny way, especially if you need a different code to get to the first one (like WHERE'S THE PASSWORD!!! "Oh, it's taped to the inside of the coffee can"... ... ... "WHAT'S THE PASSWORD FOR THE COFFEE!!!!"
EDIT: And then he tells you the password for the coffee and open the can and it's the same password, so why didn't he just tell him in the first place