## Unique Symbol Combination

Rudi
gamma jay
Posts: 25393
Joined: 17 Mar 2010, 17:33
Location: Cape Town

### Unique Symbol Combination

You are working with a 4x4 grid as in this image:

Place one of these four characters: @ # \$ % in each of the sixteen squares so that no character appears more than once in any row, any column, or any of the two main diagonals.

Use Excel or any suitable app to complete the puzzle.
There may be more than one solution based on different combinations of the four characters, but any valid solution must comply with the parameters above.
Regards,
Rudi

StuartR
Posts: 11863
Joined: 16 Jan 2010, 15:49
Location: London, Europe

### Re: Unique Symbol Combination

Spoiler
@#\$%.png
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StuartR

Rudi
gamma jay
Posts: 25393
Joined: 17 Mar 2010, 17:33
Location: Cape Town

### Re: Unique Symbol Combination

Excellent Stuart, but you didn't have to name the solution with some swear word!!
Regards,
Rudi

StuartR
Posts: 11863
Joined: 16 Jan 2010, 15:49
Location: London, Europe

### Re: Unique Symbol Combination

Rudi
StuartR

Rudi
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Posts: 25393
Joined: 17 Mar 2010, 17:33
Location: Cape Town

### Re: Unique Symbol Combination

Regards,
Rudi

HansV
Posts: 74155
Joined: 16 Jan 2010, 00:14
Status: Microsoft MVP
Location: Wageningen, The Netherlands

### Re: Unique Symbol Combination

Spoiler
If we take @ # \$ % as the first row, as Stuart has done, there are only 2 solutions: the one given by Stuart, and
S0303.png
i.e. a cyclic shift of rows 2, 3 and 4.
Since there are 4*3*2*1 = 24 possible permutations of the characters in row 1, the total number of solutions is 2*24 = 48.
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Regards,
Hans

Rudi
gamma jay
Posts: 25393
Joined: 17 Mar 2010, 17:33
Location: Cape Town

### Re: Unique Symbol Combination

Thanks for those mathematical insights. I'll take your word for it.

My attempt uses a different combination from Stuart's (and yours), but nevertheless, a valid solution to...
Spoiler
4x4 Puzzle.jpg
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Regards,
Rudi

HansV