Synthesized answer
The provided passages do not explicitly list unanswered questions. However, they suggest that Hercule Poirot's conclusion about the killer in "The Murder of Roger Ackroyd" might be flawed [1]. The text states that Poirot's solution is described as "a motiveless as it is impractical" [1].
The passages highlight that Agatha Christie, in her novel, exposed the narrator as the killer, which confounded detective story conventions [1]. Pierre Bayard, a psychoanalyst and literary scholar, offers a re-reading of the novel, challenging Poirot's conclusions and proposing a new solution to the crime [1]. While this indicates an ongoing debate or alternative interpretations regarding the murder, it does not specify what particular questions remain unanswered.
Synthesized from the book passages below. Chat with the book on Feynman for follow-up.
From the book
Title: Who Killed Roger Ackroyd? by Pierre Bayard Description: A psychoanalyst and literary scholar offers a re-reading of Agatha Christie's classic novel, "The Murder of Roger Ackroyd," challenging Hercule Poirot's conclusions about the identity of the killer and presenting a new solution to the crime. Categories: Fiction Pages: 182 Snippet: In her most famous work, the murder of Roger Ackroyd, Agatha Christie confounded the conventions of the detective story by exposing her narrator as the killer. But Hercule Poirot's solution to the crime is a motiveless as it is impractical.