There is provably no solution if the servants simply make off with everything given to them. I think we have to assume that they don't steal secured (i.e. locked with a lock) safes.
If the premise is that it is a 'logic' puzzle and in the end it depends on the cooperation of the servants then in 'real life' there would be no solution.
After all, the 'real life' problem is what sketches the background for this, otherwise why bother with that?
My personal favorite for little (smart) kids:
A farmer has to cross the river, he has with him:
- a wolf
- a sheep
- a cabbage
The boat that hast to take him across the river will only hold one item besides the farmer, what is the sequence of moves that will get the farmer and his possessions to the other side without the sheep eating the cabbage or the wolf eating the sheep ?
Respectfully (and we've communicated - so you know I mean that literally and am not being sarcastic) we'll have to disagree. I think it's reasonable that the servants don't make off with things genuinely of no value, so locked padlocks without keys, and locked safes, are "safe" and not stolen. I think it's reasonable that they make off with anything remotely of value, such as a padlock and key, or (of course) the amulet, but not the amulet when it's locked in the safe.
I agree that the farmer puzzle is nice for kids, but it yields to "try it, oh, that works, ok, I'm done." There's no real insight from it.
I figured out the answer, but only by assuming things (that they won't take a locked safe). But if I can assume that, can't I also assume they won't take a key by itself, since it has no value?
Would they take an empty safe? What about a locked padlocked, without a key, not locked onto anything?
I think it's better to make these things explicit in the puzzle.
