# Number Theory

September 18th, 2009 by ben

Exercises for Hanchan:
(note to self, move this to private/password protected tomorrow)

1) Written out in base 10, the number $345!$ ends in how many zeroes?

2) The product of the 12-digit number $493,\!224,\!762,\!945$ and the 12-digit number $471,\!910,\!894,\!925$ is the 24-digit number $232,\!758,\!139,\!280,\!5A5,\!928,\!554,\!125$. Find the digit $A$.

Hey, Ben, this is K. Apparently I can edit this. I can also see all your private posts. You should probably fix this.

Fixed. Thanks.