While reading through this brochure, you see that the sandstone that makes up the park is 320 million years old. Assumin

[answerhappygod]

While reading through this brochure, you see that the sandstone
that makes up the park is 320
million years old. Assuming that K40-Ar40 isotopes were used to
determine this age (1.2 billion
years for one half life), how many half lives would the sandstone
have gone through in order to
be 320 million years old? You have to show all your work in order
to receive credit for this
question.