how am i supposed to find out the passcode if i d ont have the answers to the hints...
This is the key part of the instructions:
I remember that if you know all the answers then you can determine the passcode, and that there are no redundant questions.
This means that if you knew the yes/no answers to each of the 5 hints, then only a single 4-digit passcode would satisfy all five of the hint answers. Additionally, it means that if you removed any one of the hints, then there would be multiple 4-digit passcodes that would satisfy all four of the remaining hint answers.
To get you started, think about the combination of hints 1 and 4. If the answer to hint 1 is "Yes", is hint 4 redundant? If the answer to hint 4 is "Yes", is hint 1 redundant?