EPTIMO 2010 results (North-Korea disqualified?) - Page 2
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Malgrif
Canada1095 Posts
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BloodDrunK
Bangladesh2767 Posts
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Nytefish
United Kingdom4282 Posts
On July 13 2010 22:04 moon` wrote: Wow.. there's a competition for this?! Props to math nerds! :p Btw, how did the North Koreans cheat? Like, with formulas tucked under their pants or something? Team leaders know the questions beforehand and could cheat by telling their contestants. But there was a question posed slightly differently in the real exam compared to the pre-exam discussion and they got caught out. This is what I heard happened previously, I don't know about this year. | ||
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Zurles
United Kingdom1659 Posts
On July 13 2010 22:32 Malgrif wrote: I read the first 5 words of a questions and i knew, without a doubt, that i'll never be able to solve one of these questions. makes me sad =( Yep, no idea how to start. it's purty hard. | ||
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Infernus
Norway222 Posts
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illu
Canada2531 Posts
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BlackJack
United States10499 Posts
On July 13 2010 21:25 ooni wrote: I liked to call Team USA, Team Asia. Click the team members to see why. . Lol I recognize a name on that team Apparently he is good at spelling too | ||
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DemiSe
883 Posts
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blankspace
United States292 Posts
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Tyri
Germany453 Posts
the gauß function manages to turn a easy problem into a really bad one  Never heard of this contest anyways | ||
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arbiter_md
Moldova1219 Posts
f(y) = f(1) * [f(y)] Now, we can have [f(y)] = 0 for all y, which means f(y) = f(1) * 0, and we get f(y) = 0 - constant wich is one solution. Or there's some y, for which [f(y)] <> 0. This means either [f(y)] < 0, and in this case f(y) <= [f(y)] < 0, which means 0 < f(1) <= 1, or [f(y)] > 0 meaning f(y) >= [f(y)] and f(1) >= 1. In case 0 < f(1) <= 1, we want to consider case y = 1, which means f(1) = f(1) * [f(1)]. And if 0 < f(1) < 1, we have [f(1)] = 0, which leads to f(1) = 0 - contradiction. So, f(1) = 1 in this case. And f(y) = [f(y)] which means f(y) is an integer for all y. In this case, we can consider y = 1, and any x to get f([x]) = f(x). Which means if n - is an integer, and a - is a real number in range [0,1), we can put x = n + a, and get f(n) = f(n + a). And finally we can consider x = n - integer, and y = (n + 1) / n. In this case, we have f(n + 1) = f(n) * [f(1)] = f(n), which means our function is a constant. By the same logic we will discover the same thing in case f(1) >= 1. The final result is f(x) is a constant, and the constant is either 0, or any number in range [1, 2). | ||
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Cloud
Sexico5880 Posts
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alffla
Hong Kong20321 Posts
On July 13 2010 22:07 Jibba wrote: Kazakh students: ![[image loading]](http://www.msminterbridge.nl/components/msm/root/images/news/kazakh_students_in_class.jpg) I actually didn't realize it either, until I saw a BBC International report on the TV and they all looked East Asian. :O girl naer the middle with grey top is cute :3 also.. HK #20 hells yea ok its not super high ranked but we're just a small city and its the world rankings :3 below Romania though...fffuuuu-  oh and lol how the NK get disqualified. haha lol wiki only shows this : North Korea was disqualified for cheating at the 32nd IMO in 1991 for the first time in the history of IMO. | ||
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hixhix
1156 Posts
edit: About NK being disqualified, IIRC when they were disqualified 10+ years ago, the coach was executed when the team went back home. | ||
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Klockan3
Sweden2866 Posts
Edit: I solved problem 1,5 and 6, don't want to bother with the geometry ones and I don't get anywhere on problem 3. Having taken a ton of maths courses really helps, the first problem is trivial then. I guess what these countries do is to teach their participants a lot of number theory and geometry so that they can solve these questions, since that is all this. Anyone know how to solve number 3? Probably something simple I just don't see right now. | ||
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Amber[LighT]
United States5078 Posts
On July 14 2010 00:05 BlackJack wrote: Lol I recognize a name on that team Apparently he is good at spelling too http://www.youtube.com/watch?v=gRZNQ06kWyc Wouldn't be surprised if he was autistic :/ | ||
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Diuqil
United States307 Posts
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hixhix
1156 Posts
On July 14 2010 04:28 Klockan3 wrote: I love the fact that Korea all scored 0 on problem 5, shows that their instructor forgot to teach them the technique needed for that problem... The problem isn't even that hard. Edit: I solved problem 1,5 and 6, don't want to bother with the geometry ones and I don't get anywhere on problem 3. Having taken a ton of maths courses really helps, the first problem is trivial then. I guess what these countries do is to teach their participants a lot of number theory and geometry so that they can solve these questions, since that is all this. Anyone know how to solve number 3? Probably something simple I just don't see right now. Go http://www.artofproblemsolving.com/Forum/portal.php?ml=1 to discuss if you like. | ||
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Hamster1800
United States175 Posts
Well I probably would have failed the geometry problems anyway. | ||
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Raisauce
Canada864 Posts
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