Testing shows that a sample of wood from an artifact contains 12.5% of the original amount of carbon-14. Given that the half-life of carbon-14 is 5730 years, how old is the artifact?
A. 22,920 years
B. 17,190 years
C. 11,460 years
D. 5730 years
If the half-life of carbon-14 is 5730 years then for every 5730 years the original amount of the carbon-14 is cut in half. So if it originally started at 100% when it was new then in 5730 years it would drop to 50%. After that, every 5730 years it drops to 25% and then 12.5% and so on.
