Problem 6:
$a$ and $b$ are two positive integers both less than $2010$; $a\ne b$. Find the number of ordered pairs $(a, b)$ such that $a^2 + b^2$ is divisible by $5$. Find $a + b$ so that $a^2 + b^2$ is maximum.
BdMO National Higher Secondary 2010/6
Re: BdMO National Higher Secondary 2010/6
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"Inspiration is needed in geometry, just as much as in poetry." -- Aleksandr Pushkin
Please install LaTeX fonts in your PC for better looking equations,
learn how to write equations, and don't forget to read Forum Guide and Rules.
Please install LaTeX fonts in your PC for better looking equations,
learn how to write equations, and don't forget to read Forum Guide and Rules.