The Question was revealed in Restaurant at the End of the Universe (as Arthur spelled it out while trying to teach the cavemen Scrabble), but it was actually

"What do you get if you multiply six by nine?"

Not by 7.

Yeah, my understanding was that the slighty wrong question was either the universe playing a horrible trick on him, or a result of the fact that the program has been screwed up. Also, I'm not so sure Arthur is part of the (correct) program being run on the Earth. It's heavily implied, if not outright stated that he's not descended from a caveman, but from a telephone sanitiser.

Okay. That clears that up, thanks.

Actually, if you work in base 13, 6x9 does equal 42. But as Douglas Adams himself said, "Nobody makes jokes in base 13."

Didn't they die out?

Also, "The Internet" tells me 6*9=42, in base 13.

The cavemen? Yeah, as far as I know. They were already being displaced by the Golgafrinchans, that's why Arthur was trying to teach them scrabble.

What game was that, BTW?

I was under the impression that the Golgafrinchans were about to die out during the winter.

I just liked the comment Arthur makes when they get the six by nine question. "I always thought there was something wrong with the universe"

Damn, you might be right. I can't remember now... the various conflicting versions of the continuity are confusing me.

It is explained later that many did die, but afterwards the survivors built a raft and set out to sea. It is implied that some of them must have survived, in order to build the human race. The books don't really leave any doubt that the Golgafrinchans are indeed our ancestors.

Hmm, I must've missed that (a possibility that's not at all unlikely). I need to read the books again.

From "Life, the Universe and Everything", chapter 2:

"What happened to the Golgafrinchans?" asked Ford.
Arthur shrugged.
"A lot of them didn't make it through the winter three years ago," he said, "and the few who remained in the spring said they needed a holiday and set off on a raft. History says that they must have survived..."
"Huh," said Ford, "well well."

While the hard winter and the raft were still in the future, it was stated in plain words in Restaurant that the Golgafrinchans would be the ancestors of modern humans.

"Put the Scrabble away, Arthur," he said, "it won't save the human race, because this lot aren't going to be the human race. The human race is currently sitting around a rock on the other side of this hill making documentaries about themselves." [Ch. 33]

Hmm. I interpreted both those as assumptions based on the uselessness of humans (correct or not), not fact.