Question: Ten little Niggers, in American reprints and adaptations were all retitled "And Then There Were None", after the last five words in the nursery rhyme that has a roud folk song index number of what?
Sentence (from "And Then There Were None"): And Then There Were None is a mystery novel by English writer Agatha Christie, widely considered her masterpiece and described by her as the most difficult of her books to write.
Relevant evidence: Yes