<PRE><B>Question 750854</B>
&lt;pre&gt;
Draw 5 blanks for the 5 digits:
&lt;u&gt; &lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt; &lt;/u&gt; 
&lt;/pre&gt;
the last is one half the second and one third the first
&lt;pre&gt;
That narrows it to these three possibilities:
&lt;u&gt;3&lt;/u&gt; &lt;u&gt;2&lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt;1&lt;/u&gt;

&lt;u&gt;6&lt;/u&gt; &lt;u&gt;4&lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt;2&lt;/u&gt;

&lt;u&gt;9&lt;/u&gt; &lt;u&gt;6&lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt;3&lt;/u&gt;
&lt;/pre&gt;
the first two digits are the square of the third
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The only one of those three that has the first two digits 
forming a square is

&lt;u&gt;6&lt;/u&gt; &lt;u&gt;4&lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt;2&lt;/u&gt;
since 64 is the square of 8.  So the third digit is 8.

&lt;u&gt;6&lt;/u&gt; &lt;u&gt;4&lt;/u&gt; &lt;u&gt;8&lt;/u&gt; &lt;u&gt; &lt;/u&gt; &lt;u&gt;2&lt;/u&gt;
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the last two digits are the sum of the second and third
&lt;pre&gt;
4+8=12 so the last two digits is 12, which means the
fourth digit is 1
&lt;u&gt;6&lt;/u&gt; &lt;u&gt;4&lt;/u&gt; &lt;u&gt;8&lt;/u&gt; &lt;u&gt;1&lt;/u&gt; &lt;u&gt;2&lt;/u&gt;

That&#39;s the answer!

We didn&#39;t need to use:
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the third is double the second,
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But it checks since 8 is indeed double 4
We also didn&#39;t need to use
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The sum of all the digits is 21.
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But it checks also since 6+4+8+1+2 = 21 

Edwin&lt;/pre&gt;</PRE>