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 is sixty,I know.And that is twice thirty.So I am twice eighteen.That is thirty-six ,isn't it?