[JenB]

Yes, but HitchHiker's Guide was never specific on what base the ultimate answer was in. Why assume 10? That's decimalism. Maybe the pan-dimensional mice use base 13, and therefore their computers are based on 13. In which case, 6x9 = 42 base13

[ThinkDifferent]

That's decimalism. Maybe the pan-dimensional mice use base 13, and therefore their computers are based on 13.

Douglas Adams claimed that base 13 was a coincidence, but clearly it's a result of his subconscious being affected by the Earth's programming. At any rate we should now move on to the Ultimate Meta-Question: What is the significance of the Ultimate Question?