Comments on: I missed the deadline http://samjshah.com/2008/05/08/i-missed-the-deadline/ Tue, 15 May 2012 22:49:27 +0000 hourly 1 http://wordpress.com/ By: Monday Math Madness #5: We have a winner » Fun Math Blog http://samjshah.com/2008/05/08/i-missed-the-deadline/#comment-83 Sat, 10 May 2008 17:14:53 +0000 http://samjshah.wordpress.com/?p=169#comment-83 [...] missed the deadline but blogged about it, providing a brute force [...]

]]> By: samjshah http://samjshah.com/2008/05/08/i-missed-the-deadline/#comment-81 Thu, 08 May 2008 21:48:06 +0000 http://samjshah.wordpress.com/?p=169#comment-81 Thanks.

Yup… Simpler… I always tend to get caught up in things… I went one extra digit than I needed…

]]> By: Johan P http://samjshah.com/2008/05/08/i-missed-the-deadline/#comment-80 Thu, 08 May 2008 20:30:41 +0000 http://samjshah.wordpress.com/?p=169#comment-80 Just wonder about this:
(a + b)² = a² + 2ab + b²
Since we are looking for squares with all odd digits we can drop even squares.
If we say, like you did, that b stands for the one-digit and a for all the rest, there follows that (a+b)² always contains an even digit on the second place. Because: b² is either 01, 09, 25, 49 or 81. a² is always something of the form x00.2ab is always even.
So the sum of b² and 2ab gives you an even digit in the second place.

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