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- Thread starter wellorderingp
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With an exception to 5

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Char. Limit

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Therefore, all primes must end in 1, 3, 5, 7, or 9.

Consider: With the exception of 5, no primes can end in 5, as if they do so, then they are a multiple of 5.

Therefore, all primes must end in 1, 3, 7, or 9.

So... yes.

If you need a proof of either of the considered statements, I'm sure it wouldn't be too difficult.

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bah, beat me to it. :)

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Yeah that was pretty simple :) thanks anyways

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Char. Limit

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Interesting. This means to me that there are about as many primes that end in 3, as there are primes that end in 1 (or 7 or 9). I wonder if this has been proven.

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Ah, here we go: http://en.wikipedia.org/wiki/Dirichlet's_theorem_on_arithmetic_progressionsInteresting. This means to me that there are about as many primes that end in 3, as there are primes that end in 1 (or 7 or 9). I wonder if this has been proven.

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