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 Post subject: 2009
PostPosted: Tue, 6 Jan 2009 05:03:45 UTC 
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1 ? 2 ? 3 ? 4 ? 5 ? 6 ? 7 ? 8 ? 9 = 2009

? restricted to + - * /
Only one set of brackets allowed

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PostPosted: Wed, 7 Jan 2009 20:29:33 UTC 
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In the absence of bracketing, are the standard precedence rules applicable or are operations evaluated from left to right? Does each "?" symbol have to be replaced by exactly one operational symbol (not counting brackets)?


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PostPosted: Wed, 7 Jan 2009 22:32:22 UTC 
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Spoiler:
Since 9*8*7=504, only one set of parentheses is allowed, and / is a bit expensive, lets consider at least product of three consecutive numbers and see if a multiple is close to 2009. Obviously 2010=1*2*3*335 but that doesn't look doable. The next one is 2016 =1*2*3*336=2*3*4*84=6*6*7*8=4*7*8*9. The 6*7*8 one gives us
1*2-(3-4-5)*6*7*8-9=2009.


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PostPosted: Thu, 8 Jan 2009 04:29:11 UTC 
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Right on, O.M. :idea:

Ok, Skip?

Same thing, but MUST use at least 5 *'s ; 2 sets of brackets allowed.

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