"When do you expect to be able to determine the age of this place?"
It was always difficult to determine the age of a London building.
The thorium-232 to uranium-238 ratio was used to determine the age.
Various properties of stars can also be used to determine their age.
These hard parts are used to determine the age of each fish selected.
However, "any attempt thus to determine the age of the world has been long since abandoned."
It was immensely important to him to determine her age.
Few people could have determined the blind man's age by looking at him, but certainly his youth was decades past.
It is expected that these details will help determine age and behavior of the cats.