Congrats to Nelzi and Dub for getting the farmer one, and to Nelzi for getting the coin one! 
Their answers basically boil down to this:
Also well done to Alyzarin for getting the hardest bit of the prisoner puzzle, which is probably the hardest puzzle so far. There's still a little problem, though: what if the light is on at the beginning? Then the counter would turn it off and count it as a prisoner. But then he'd prematurely tell the warden they'd all been.
Dianeva, given the way I phrased the question, I believe that's a fair answer. Clever. The warden could easily break it of course, if he were so inclined, by never selecting one of the prisoners on their day, for instance. But I did say he did it randomly, so you could be certain that eventually he would choose the prisoner on their day. How about a very slightly different puzzle where the warden can do such things; the only thing he promises is that each prisoner can always be sure he'll take them to the bathroom eventually (including if they've been before). Alyzarin's solution goes a long way to solving this but isn't quite there.
Edit: Thanks Snowycat for the new riddle. Unfortunately I've seen it before, but it's a nice one!
Bookmarks