Skeletal remains had lost 70% of the C-14 they originally contained. Determine the approximate age of the bones. (Assume the half life of carbon-14 is 5730 years. Round your answer to the nearest whole number.)

Answer 1

the fraction remaining after t years is

(1/2)^(t/5730)

So, you want

(1/2)^(t/5730) = .7
t/5730 = log(.7)/log(.5)
...