In seven houses there are seven cats. Each cat catches seven mice. Each mouse would have eaten seven ears of corn and each ear of corn, if sown, would have produced seven gallons of grain. How many things are mentioned in total?
This is strikingly similar to the Cornish riddle:
As I was going to St Ives, I met a man with seven wives. Every wife had seven sacks. Every sack had seven cats. Every cat had seven kits. Kits, cats, sacks, wives. How many were going to St Ives?
Eerie to be sure. The answer to the Rhind Manuscript: 19,607. The answer to the Saint Ives riddle: 1, as the narrator is going to Saint Ives and the animal loving, luggage laden bigamist party is going the other way. Samuel L. Jackson provides the same number in Die Hard with a Vengeance but explains the answer with colorful explanation something to the effect of "the man's got seven wives. He ain't going nowhere." (I think the original has cursing).