Rearrange the key caps of the 1 through 9 on a numeric keypad so that no cap is on its correct key, in such a manner that each of the three rows forms a 3-digit perfect square.

  
789
456
123
  

Using an Excel table and a list of 3 digit squares the following is my derivation:

    Keypad    Rearrange  Not in Key_Pos       Square Test   
     789             361           ???                      361    19
     456             529           ???                      529    23
     123             784           ???                      784    28

I was not as logical as either of the prior posters but with the appropriate formulae this does work.  The array in the middle column tests a cell in the first array against the corresponding position in the second.  It returns an alert if the values match [=if(c2=g2,"!","")].

Posted by brianjn on 2011-04-16 06:42:39