That was actually the problem that first got me interested in math.  The whole "roll several dice, take the top n" was a common trick we used in D&#38;D games, and I wanted to know what the odds were of getting different outcomes, and how it varied by number of dice.  I actually worked out the 4 dice version by hand before trying to get smarter about it.  And eventually did.<p>So when I saw Project Euler I dusted off the problem, and tried to set up a variant that was about the right level of difficulty for a Project Euler problem. :-)