A woman was having some trouble with her heart, so she went to see the doctor. He was a new doctor, and did not know her, so he first asked some questions, and one of them was, How old are you?"
"Well，"she answered, "I don' t remember, doctor, but I will try to think, "She thought for a minute and then said ，"Yes, I remember now, doctor When I married, I was eighteen years old, and my husband was thirty. Now my husband sixty, I know. And that is twice thirty, So I am twice eighteen. That is thirty-six, isn't it？