Carbon-14 is a radioactive isotope of carbon which has a half-life of about 5600 years. Let R be the nearly constant ratio of corbon-12 found in the atmosphere. Let r be the ratio of carbon-14 to carbon-12 found in an observed specimen. It has been shown for carbon-14 dating of objects that

R = re (tIn4/5600) Where t is the age of the object in years. Suppose a specimen has been found in which

r = 0.2R, find the age of the specimen