An Old Bone Sample Contains $321 \mathrm {~g}$ Of Carbon and Has an Activity of 947 Decays/min Due

Short Answer

An old bone sample contains $321 \mathrm {~g}$ of carbon and has an activity of 947 decays/min due to the carbon-14 in it. The half-life of carbon-14 is $5730 \mathrm { y }$ . Assume that the activity of the atmospheric carbon is, and has remained, $0.255 \mathrm {~Bq}$ per gram of carbon.
(a) How old is the sample?
(b) What will be the activity of the sample $2000 \mathrm { y }$ from now, in decays per minute?