How elderly people lived in ancient Rome and Greece?
About 5 percent of ancient Rome's population was over age 65. Considering that Rome's population was about one million in 5 B.C., about 50,000 of the people were over age 65.
Sources:
http://www.utexas.edu/depts/classics/documents/Life.html
http://www.usefultrivia.com/history_trivia/history_trivia_008a.html
I'm sorry -- but I just reread your question.
Most elderly people lived with their children and grandchildren in ancient Rome and Greece.