Some problems to solve

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Please don't post problems (by starting a topic) in the "X: Solved" forums. Those forums are only for showcasing the problems for the convenience of the users. You can always post the problems in the main Divisional Math Olympiad forum. Later we shall move that topic with proper formatting, and post in the resource section.
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Labib
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Re: Some problems to solve

Unread post by Labib » Fri Dec 02, 2011 9:02 pm

nafistiham wrote: $ (A+Z)+$$2(B+C+D+........Y)$$=325 $
$ \Rightarrow (A+Z)+$$2{(B+C)+(D+E)+(F+G)+......(X+Y)}$$=325 $
Please edit it...
:?

I used the same approach except for the part of generalizing the equations. :)
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nafistiham
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Re: Some problems to solve

Unread post by nafistiham » Sat Dec 03, 2011 6:09 pm

done.
thanks,vya.i used just "{}".that's why it didn't work.
\[\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0\]
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Abdul Muntakim Rafi
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Re: Some problems to solve

Unread post by Abdul Muntakim Rafi » Mon Dec 05, 2011 1:27 am

Labib, we need a way to solve $3$... How can we be sure that these two are the only possible answers...
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*Mahi*
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Re: Some problems to solve

Unread post by *Mahi* » Tue Dec 06, 2011 12:19 am

Use the rules of $a^3+b^3 $ and $a^3-b^3$ (I think a part requires $(x+y)^3-1^3$)
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Re: Some problems to solve

Unread post by *Mahi* » Tue Dec 06, 2011 12:21 am

That way directly yields $x+y=1$ or $x-1=y-1=0$
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Abdul Muntakim Rafi
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Re: Some problems to solve

Unread post by Abdul Muntakim Rafi » Mon Dec 12, 2011 10:16 pm

Mahi... Can you please elaborate your answer? I didn't understand...
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Re: Some problems to solve

Unread post by Dipika » Thu Dec 22, 2011 9:54 am

(1,0), and (0,1) are the another solutions for the problem 3.

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sm.joty
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Re: Some problems to solve

Unread post by sm.joty » Thu Dec 22, 2011 5:05 pm

কেউ কি বগুরার ২০১১ এর HSC ০৪ নাম্বারটা সল্ভ করতে পারছ। সোজা জিনিস কিন্তু দসমিক সংখ্যা কিভাবে বাইনারিতে নেব সেটা বুঝতেসি না। উদাহরন আবশ্যক। :D
$(1)_2+(0.1)_2+(0.01)_2+\cdots\cdots = ?$
হার জিত চিরদিন থাকবেই
তবুও এগিয়ে যেতে হবে.........
বাধা-বিঘ্ন না পেরিয়ে
বড় হয়েছে কে কবে.........

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Labib
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Re: Some problems to solve

Unread post by Labib » Thu Dec 22, 2011 6:39 pm

Here's a conversation between me and DJ which might help.
Me::ডিজে...
"$.1$ পৌনপনিক কে বাইনারীতে কি লিখে?? ঃ-s"
DJ::
"$0.0(0011)$ বন্ধনীর ভেতর পুনঃপৌণিক।"
Me::
"মাথার উপর দিয়ে গেল :(
একটু ব্যাখ্যা দাও না!"
DJ::
"‎$0.1$ পৌণপৌণিক $= 1/9 = (2^-4 + 2^-5) + (2^-8 + 2^-9) + (2^-12 + 2^-13) + (2^-16 + 2^-17) + .....$"

@Joty
শুধু $1$ যোগ করলেই পারো।
তবে আমার মনে হয়, উত্তর ১০ হতে পারে যদি তুমি $.9999999999999...=1$ এর মতো চিন্তা করো। :)
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Dipika
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Re: Some problems to solve

Unread post by Dipika » Fri Dec 23, 2011 9:53 pm

Actually (n,1-n) is the solution of the problem 3..
In the divisional math Olympiad it was asked to find out the value of x-y=?
so the answer will be 2n-1

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