Of course! The experiment. To find a question with that answer. Is going on all around us. Here. The earth. The ground. The trees. The water. The rocks. The cavemen.
16 seconds sound clip from The Hitchhiker's Guide to the Galaxy (1981) - Episode 6 sitcom.
You can hear this line at 00:31:00.945 in the Blu-ray version of the TV Series.
Quote context
[...]
- Hmm. Poor bloody caveman. It's all been a bit of a waste of time for you, hasn't it?
- Out-evolved by a telephone sanitiser.
- He's pointing at the Scrabble board.
- Oh, he's probably spelt library again with one 'R.'
- 42.
- What?
- The Golgafrinchans. Us. Just by arriving here.
- The caveman is part of the programme. And they're dying out because of us, therefore no question.
- Marvin said the question was printed in my brain-wave patterns.
[...]