Let x and y be two integers with 1<x<y and x+y≤100. Sally is given only their sum x+y and Paul is given only their product xy. Sally and Paul are honest and all this is commonly known to both of them.
The following conversation now takes place:
- Paul: I do not know the two numbers.
- Sally: I knew that already.
- Paul: Now I know the two numbers.
- Sally: Now I know them also.