(solution) An archaeological sample contains .755 curies of lead-206

(solution) An archaeological sample contains .755 curies of lead-206

An archaeological sample contains .755 curies of lead-206 and 1.455 curies of uranium-238. Assume that all the lead now present in the rock came from the radioactive decay of the uranium and that no appreciable amounts of other radioactive nuclides are present in the sample. The half-life of uranium-238 is 4.51 x 109 years. What is the age of the sample?