How many pages in The Hitchhiker's Guide to the Galaxy?

Douglas Adams wrote seven novels, one non-fiction book and two dictionaries. The orgianl radio scripts from his BBC series "The Hitch Hiker's Guide to the Galaxy" were also published in book form. "The Salmon of Doubt" was posthumously published and included an unfinished novel he was working on before his death along with other works.

Works: The Hitch Hiker's Guide to the Galaxy, The Restaurant at the End of the Universe, Life the Universe and Everything, So Long and Thanks for all the Fish, Mostly Harmless, Dirk Gently's Holistic Detective Agency, The Long Dark Tea Time of the Soul, Last Chance to See, The Meaning of Liff (co-author, dictionary), The Deeper Meaning of Liff (co-author, dictionary)