I won’t repeat the question (#12 - the fourth day) but for the last of the lady or tiger set in chapter 2 I believe either the solution is problematic or how parts of the puzzle is worded are problematic.
I believe this is mainly due to that from sign 3 and sign 5 he uses the word “either” as in either A or B when it’s pretty clear from the solution he means Logical OR, but where I and others would be only be able to understand it as Logical XOR. If you assume logical XOR the Lady can be in either room 1 or room 7.
See these two Solutions where (b) is the solution given and (a) is also valid given “either” means XOR.
If the above reasoning is correct then it would be better if the puzzle just dropped the word “either.”
While ‘either’ is indeed often used to express an exclusive or, this is not a hard rule. Consider some who says:
‘I want to be either rich or happy’
Do you think this person will mind if they turn out to be rich and happy? No, of course not.
So, despite the use of ‘either’, the speaker is expressing an inclusive or, rather than an exclusive.