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 Post subject: 2009Posted: 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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 Post subject: Posted: 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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 Post subject: Posted: Wed, 7 Jan 2009 22:32:22 UTC
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Joined: Mon, 29 Dec 2008 17:49:32 UTC
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Location: NCTS/TPE, Taiwan
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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 Post subject: Posted: Thu, 8 Jan 2009 04:29:11 UTC
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Right on, O.M.

Ok, Skip?

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

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