njvrzm, I've been enjoying the discussion here, and I've just written a little solver for this puzzle. Now I'm curious if you consider this updated puzzle broken as well:
I've forgotten my 4 digit passcode!
Fortunately, I saved some hints on my phone. All the hints have a yes/no answer. I remember that if you know all the answers then you can determine the passcode.
The hints are:
- Is the first digit smaller than the second digit?
- Is the second digit smaller than the third digit?
- Is the third digit smaller than 4?
- Is the first digit even?
- Is the fourth digit smaller than the sum of the first two digits?
Unfortunately, to access the answers to the hints, I need to log in to my phone with my passcode :(
(Notes: There's no information about redundancy of the hints. Also, this puzzle has a unique solution)