April 11, 2007 1:48pm CST
Four Doors You are an expert on paranormal activity and have been hired to locate a spirit haunting an old resort hotel. Strong signs indicate that the spirit lies behind one of four doors. The inscriptions on each door read as follows: Door A: It's behind B or C Door B: It's behind A or D Door C: It's in here Door D: It's not in here Your psychic powers have told you three of the inscriptions are false, and one is true. Behind which door will you find the spirit? The spirit lies behind Door D. If the spirit is behind Door A, then both B and D are true. If the spirit is behind Door B, then both A and D are true. If the spirit is behind Door C, then A, C, and D are all true. If the spirit is behind Door D, then the statements on all the doors are false, except for that on Door B. This matches the rules, and therefore, the resort hotel spirit lurks behind Door D.