Determaining a Person's Age

Factual Questions
1

While watching an old “Beverly Hillbillies” episode I came across this question.

Jed) How old are you Granny
Granny) I don’t right know Jed
Elly) Well how old are the hills?
Jed) What?
Elly) Well everyone back home says you’re as old as the hills.

Is it possible thru use of like DNA or measuring a person’s bone growth or some other physical thing to determain how old they are.

I’m guessing no? But if this is so then how close can they come? Within like 10 years? 5 Years?

2

In living adults, radiographs (x-rays) of the teeth, and measurements of the pulp, are one method of estimating age. The mean error is plus or minus 10 years for adults over 40.

3

Granny (Irene Ryan) died of a brain tumor on April 26, 1973 at the age of 71.

4

Cut 'em in half, and count the rings?