42
This is where I point out that the answer was wrong.<p>In HHGTG, a massive computer was built to answer the Question. The computer spent millions of years calculating, and arrived at the answer "42". The problem, it said, was that the Question had never been formulated. The computer then designed another computer to calculate the Question. After millions of years of calculation, this computer was inadvertently destroyed. The last remnants of the computer were only able to provide the question "What is six times nine?"<p>Also, knowing the answer without knowing the question is Jeopardy!