[douglas]

I've read all five books, and I don't think the ultimate question is ever revealed, but there is one attempt to figure it out by having Arthur Dent, the last surviving component of the supercomputer known as Earth that was destroyed 5 minutes before solving the problem, pull scrabble tiles from a bag without looking. They come out in this order: "whatdoyougetwhenyoumultiplysixbynine".