Round 3

For discussing Olympiad Level Number Theory problems
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Nadim Ul Abrar
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Re: Round 3

Unread post by Nadim Ul Abrar » Sat Dec 31, 2011 8:55 pm

*Mahi* wrote:Easy solution of $\boxed 8$
Let $p > q \geq r$
Then $p > \frac {q+r} 2$
But the highest divisor of $n$ may be $\frac n2$
Do the rest :)
Let $p \geq q \geq r$
Then $p \geq \frac {q+r} 2$
But the highest divisor of $n$ may be $\frac n2$
so $p= \frac {q+r} 2$ cz $p$ is not equal to$ q+r$

$r=2p-q $
now $q|3p+q$
or $q|3p $
or$ q=3,p $
if $q=p $then$ r=p$ too

and if $q=3$ then$ 2p-3|p+3$ . so $p\leq5$ .
$p=5$ doesnt work . if$ p=3$ then $r$ is also $3$ and if $p=2$ then $r=1$ .

hance all solution is $p=q=r $.. right ?
$\frac{1}{0}$

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*Mahi*
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Re: Round 3

Unread post by *Mahi* » Sat Dec 31, 2011 9:29 pm

The solution is a lot easier... we have just proved $p > \frac {q+r} 2$ is not possible, right? Then $p=q \geq r$.
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