What is the standard of care owed by an invader to an invitee?

The standard of care owed by an invitor to an invitee was stated by Willes J. in Indermaur v. Dames (1866), L.R. 1 C.P. 274 at 288, to be as follows: “And, with respect to such a visitor at least, we consider it settled law, that he, using reasonable care on his part for his own safety, is entitled to expect that the occupier shall on his part use reasonable care to prevent damage from unusual danger, which he knows or ought to know; and that, where there is evidence of neglect, the question whether such reasonable care has been taken, by notice, lighting, guarding, or otherwise, and whether there was contributory negligence in the sufferer, must be determined by a jury as matter of fact.”