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Recursive Puzzle (Posted on 2006-08-23) Difficulty: 4 of 5
Let N equal the number of words blacked out in this Recursive Puzzle.

N people before you have seen and successfully solved the Recursive Puzzle. After each person solved it, another word was blacked out. Can you solve it too?

Four wires connect to four plugs. I can't just give it away by saying, "The cyan wire goes here and the blue wire goes there," but I can tell you which plugs and which wires do not match.

The second plug does not go with the ███ wire, the third plug not with the teal wire, and the fourth plug not with the ███. The aqua wire does not go with the third plug, the teal wire not with the fourth plug, and the cyan wire not with the ███.

Solve this puzzle by matching all the colors and numbers. After you've solved it, can you pick another color or number to black out so the next person may solve it?

  Submitted by Tristan    
Rating: 4.4000 (5 votes)
Solution: (Hide)
The puzzle would have originally given six clues, but three of them have been damaged. In order for the first person to have been able to solve it, none of clues could have been redundant (because it is impossible to match four pairs of objects with less than six clues of this sort).

Let's draw a standard logic grid, except there will be question marks on the sides to indicate that a non-redundant x belongs somewhere in that row or column.

     1 2 3 4
aqua     x
teal     x x
cyan         ?
       ?   ?
What is required in order for all six clues to be non-redundant? There must be 3 Xs in one column, 2 in another, 1 in another, and none in the last. Similarly, there must be rows with 3, 2, 1, and 0 Xs. With this in mind, there are only really six possibilities to check. For each possibility, imagine you were the third person, and check that the puzzle is solvable when you know one of the clues. This should be enough to eliminate all but one possibility, but I will skip these details.

The only colors or numbers that can be crossed out are "cyan" in the third paragraph, and either "four" in the third paragraph, though this is perhaps debatable.

1 - cyan
2 - teal
3 - blue
4 - aqua

Comments: ( You must be logged in to post comments.)
  Subject Author Date
re(2): Solution for first part (figuring out the wires)Dej Mar2006-08-24 15:18:50
re(2): Solution for first part (figuring out the wires)Avin2006-08-24 08:52:13
re: Solution for first part (figuring out the wires)bumble2006-08-23 17:47:45
Some ThoughtsSolution for first part (figuring out the wires)Avin2006-08-23 16:35:32
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