For a carbon sample (C14), T1∕2=5730 year Decay constant, K‌=‌
0.693
T1∕2
‌=‌
0.693
5730
‌=1.209×10−4∕‌ year ‌ The rate of counts is proportional to the number of C14 atom in the sample N0=100,N=75 The age of the sample is given as, t‌=‌