Question: A son's age is the age of his dad's age's digits added together. The son is not nine or older. The dad is of legal age. The dad's age doesn’t end in a zero, and is more than twenty, but less than twenty-five. How old is the dad, and how old is the son?
Answer: The son is three, four, five, or six. If he is three the dad is twenty-one, if he is four the dad is twenty-two, etc.