An ancient artifact is found to have a ratio of C-14 to C-12 that is 1/8th the ratio of C-14 to C-12 found in objects today. How old is the artifact of the half like of C-14 is 5715 years?
k = 0.693/t1/2
Calculate k.
Then ln(No/N) = kt
No = 8
N = 1
You know k, solve for t.
Post your work if you gt stuck.