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The fifth number Algebra, arithmetic  Weight: 3 Liked the puzzle: 100% 09.01.2010
The set of numbers 1,3,8,120 has a remarkable property: the product of any two numbers is a perfect square minus one. Find a fifth number that could be added to the set preserving its property.
Comments:   4 check your solution  

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idler_
 
Rating: 106
Group: Moderators
2011-01-28 19:39:19
Reserved.
dddfff
 
Rating: 228
Group: Moderators
2011-02-25 02:08:27
It is not clear what "number" means.
[deleted.]
alan
 
Rating: 231
Group: Moderators
2011-02-25 09:28:56
dddfff 2011-02-25 02:08:27
It is not clear what "number" means.
[deleted.]

Since we are talking about "perfect square", it has to be an integer number.
zzz123
 
Rating: 72
Group: Members
2011-03-22 07:30:48
[deleted]



 
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