We're all agreed on the meaning of (a), ie for an "unchaptered" edition its a straight 10%.

If it's a chaptered, 100 page edition, query whether it's

(1)10 pages or 1 chapter, whichever is the lesser (Faldage, Capfka) or
(2)10 pages or 1 chapter, whichever is the greater (Bingley, Bean)or
(3) 10 pages of 1 chapter; or 1 chapter (being less than 10 pages) + odd pages to take it up to 10 pages in total (maahey).

I've got to say (1) is odd because you're penalised simply on account of the book being chaptered rather than unchaptered. (3) is unlikely because surely then there's no difference between (a) and (b) in the provision. I think that (2) does seem to be the most likely...

Thanks for all your inputs.... Send me your invoices,