Someone thinks of two
numbers between 2 and 99 inclusive.
He then adds them up and whispers the sum to Mr. Sum.
He also multiplies them together and whispers the product to Mr.
The following conversation
Mr Product: I don't know
what the two original numbers were.
Mr Sum: I already knew that you didn't know.
Mr Product: Well now I know.
Mr Sum: Aha! So do I.
What were the original
(Thanks to Ed Severn for this problem.)
Robinson Children Problem