If you want a spoiler: http://ariya.blogspot.com/2007/11/random-number-15-to-17.html http://ariya.blogspot.com/2007/11/random-number-15-to-17.htm... He gives

If you want a spoiler: http://ariya.blogspot.com/2007/11/random-number-15-to-17.html http://ariya.blogspot.com/2007/11/random-number-15-to-17.htm... He gives a few different ways to solve it, most with uniform distribution.