You are a spy in a hostile country, trying to escape the local authorities. As a disguise, you join the local Knavy, which is like a navy, but is made up entirely of knaves (people who alternate telling the truth and lying). You get word that a ship, the HMS Levik is docked in the harbor to help you escape. The problem is, there are five ships in port (at docks one through five) and none of them are marked with a name.
  You manage to talk with two old sea captains in the Knavy about which ship is which. They talk some, but you don't know if their first statement is a truth or a falsehood.
  Based on their curious descriptions, can you figure out which ship is the HMS Levik?

CAPT. HUDSON:
1. The Salamander is not moored next to the Revenge.
2. The Antimony is moored at dock one.
3. The Levik is moored at dock two.
4. The Defiance is moored next to the Levik

CAPT. BAFFIN
1. The Defiance is not moored at dock two.
2. The Levik is moored at dock four.
3. The Salamander is moored next to the Revenge.
4. The Antimony is not moored next to the Salamander.

There are four possibilities since each captain can start out with T or F. I labelled it TT, TF, FT, and FF (with the first letter representing Captain Hudson), where the letters represent the truth to the first statement.

TF is impossible since Hudson says Levik is at Dock Two and Baffin says it's at Dock Four.

TT and FF are impossible also since they contradict each other in regards to the Salamander and the Revenge being next to each other.

By elimination, FT is the only possible solution. This translate to the following criteria:

1. The Salamander is next to the Revenge.
2. The Antimony is at Dock One.
3. The Levik is not at Dock Two.
4. The Defiance is next to Levik.
5. The Defiance is not at Dock Two.
6. The Levik is not at Dock Four.
7. The Antimony is next to the Salamander.

This means that the Antimony is at Dock One. The Salamander is at Dock Two. The Revenge is at Dock Three. The Defiance is at Dock Four. The Levik is at Dock Five.

Posted by np_rt on 2004-05-27 13:07:33