There are $25$ two-digit numbers divisible by $4$ $(00 $ to $ 96)$.
$9$ of them are congruent to $0$ $(mod 3)$.
There are only $1$ non zero even digit congruent to $0$ $(mod 3)$. So in this case there are $9$ solutions.
Again, $8$ of them are congruent to $1$ $(mod 3)$.
There are only $2$ non zero even digit congruent to $-1$ $(mod 3)$. So in this case there are $16$ solutions.
The $8$ numbers left are congruent to $-1$ $(mod 3)$.
There are only $1$ non zero even digit congruent to $1$ $(mod 3)$. So in this case there are $8$ solutions.
So, there are $33$ solutions in total.
গনিত ইশকুলের সমসসা-০১
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- nafistiham
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Re: গনিত ইশকুলের সমসসা-০১
thanks vaia. beautiful solution
\[\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0\]
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- bristy1588
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Re: গনিত ইশকুলের সমসসা-০১
http://www.matholympiad.org.bd/forum/vi ... =20&t=1437
এইখানে আছে প্রবলেম...
এইখানে আছে প্রবলেম...
Please Install $L^AT_EX$ fonts in your PC for better looking equations,
Learn how to write equations, and don't forget to read Forum Guide and Rules.
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." - Sherlock Holmes
Learn how to write equations, and don't forget to read Forum Guide and Rules.
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." - Sherlock Holmes
- nafistiham
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Re: গনিত ইশকুলের সমসসা-০১
@bristy apu
couldn't you just visit the first page of the thread?
by the way the problem is from previous regional math Olympiad and pressed in GONIT ISHKUL
couldn't you just visit the first page of the thread?
by the way the problem is from previous regional math Olympiad and pressed in GONIT ISHKUL
\[\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0\]
Using $L^AT_EX$ and following the rules of the forum are very easy but really important, too.Please co-operate.
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- bristy1588
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Re: গনিত ইশকুলের সমসসা-০১
লাবিবীয় সমাধান চরম হইছে।
আর এই ভুল যে কতবার করলাম সমস্যাটাই উলটা বুঝছিলাম আগে।
আর এই ভুল যে কতবার করলাম সমস্যাটাই উলটা বুঝছিলাম আগে।
হার জিত চিরদিন থাকবেই
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বড় হয়েছে কে কবে.........