man with three dogs

A man has three dogs. A second man asked him the ages of his dogs. The first man told him that the product of their ages was 36. After thinking the second man was unable to find the answer and asked for another clue. The first man replies the sum of their ages is equal to your sons age. Still the second man was unable to answer and asked for another clue. The first man told him that his youngest dogs name was Rex, and suddenly second man gave the correct answer.

Explain how?


This is extremely difficult, wacky logic is required. All information required is given!!!

Do not try to solve this problem as the second man.....


Once again this riddle will generate witty remarks which in themselves will be humorous.....