Corrected entry: Arthur and Ford find the ultimate question by taking letters at random from a Scrabble set - spelling 'What do you get if you multiply six by nine' - and the words 'Forty' and 'Two' are already on the board. That is five Ys - and there are only two Ys in a Scrabble set.
Corrected entry: Before Zaphod, Arthur, Ford and Trillian enter the lift after talking to the mice, Trillian wears a dull red suit which hasn't been done up much. However when they leave the lift Trillian's suit is shiny and is considerably more done up. Her suit stays like this until in Episode 5 after the book explains Milliways when it suddenly changes back.