All living things contain carbon. Most of this carbon is stable carbon-12. Nevertheless, a small percentage will be carbon-14, a radioactive isotope of carbon that decays with time. As living things eat and breathe, carbon is constantly recycled as well as therefore the percentage remains constant. It's not until death that the percentage of carbon-14 will begin to diminish due to decay. Consequently, it is extremely easy to find out how long a fossil has been dead. The half-life of C-14 is 5730 years.
A fossil was analyzed and determined to have a carbon-14 level that is 64.0 % that of living organisms. How old is the fossil?