Juha Saukkola
476
238
510


Hi ed
Answer to the 3x3 GCD17 puzzle posted 20-June is as follows
425
731
680
Regards
Pete Kogel


ed:
i've tinkered around with some algorithms and have come up with a couple of 
answers for the challenge, here they are:
[ [ 4  2  5 ] , [ 7  3  1 ] , [ 6  8  0 ] ]
[ [ 9  1  8 ] , [ 3  0  6 ] , [ 5  2  7 ] ]
perhaps a bit "cheating" to write a program to find them, but it was 
interesting nonetheless. They all seem to check. All six rows/columns are 
divisible by 17.
-Regards,
David Perryman


> The greatest common divisor for 3x3 squares using 0-9 without
> repetition is 17.
 935
 102
 867
-- 
Roger Phillips, senior software engineer 


I believe your Number Squares Puzzle has two different solutions:
 425
 731
 680
and
 918
 306
 527
Peter Exterkate


Ed --
I don't know if this is unique, I found it by hacking and slashing as usual.
425
731
680
Was the puzzle correctly specified? 0-9 without repetition is 10 digits, 
which don't fit. I didn't use the 9.
Method: List all 53 3-digit multiples of 17. Eliminate the 14 that contain 
repeating digits. Notice the most constraining digits (there are only 3 
multiples beginning with 2, for example) and use those to abbreviate 
testing of combinations. Fill the left column and top row first during each 
test, not using any multiples that contain zeroes. 1, 2, 3 ruled out as 
upper left digits by trying each combo and finding spots that can't be 
filled from the menu of legal multiples. 4 works, as above. There may be 
more, but laziness sets in.
Take care --
David Yamanishi



{425, 731, 680}
George Tolley


918
306
527
Whew!
--mathidentity


An exhaustive search doesn't take long:
 
425
731
680
j k mclean


Hi Ed,
       Yes!!!
             935
             102
             867
       Alastair Cuthbertson


918
306
527
Thanks, Jeff Gosselin.


Using 0-9 was a bit difficult - trying to put 10 digits in 9 slots
0-8 will yield
 204
 357
 816
Bill Downs
Mableton, GA  30126