Question

An artifact was found with 63.8% of Carbon 14, how old is the mummy, assuming the half-life of Carbon 14 is 5730 years.

Answer 1

.638 = 1(1/2)^(t/5730)
log .638 = (t/5730)log .5
t/5730 = log .638/log .5 = .64837...
t = appr 3715 years

Answer 2

A scientist determined that the bones from a mastodon had lost 79.579.5​% of their​ carbon-14. How old were the bones at the time they were​ discovered?