According to a supercomputer that was given a grant by the Galactic Coalition of Advanced Mathematics, the answer to life's ultimate question is, in fact, 42.
This answer, discovered by the great mathematician Deep Thought, was arrived at through an 11-million-processor supercomputer that was fed all the knowledge of human civilization.
However, when the question was asked, the supercomputer was not actually asked to come up with the answer, but rather, "What's the answer to the ultimate question of life, the universe, and everything?"
So, in short, the answer to the ultimate question is 42.