Question

An anthropologist finds there is so little Carbon-14 remaining in a prehistoric bone that instruments cannot measure it. This means there is less than 0.2% of the amount of Carbon-14 the bones would have contained when the person was alive. How long ago did the person die? (The constant for Carbon-14 is 0.00012.)
Answer
13,411 years
22,491 years
45,020 years
51,788 years