Question #d0547

1 Answer
Mar 3, 2016

21000 "years"

Explanation:

For each half-life, the amount of "C"-14 would be halved. So after x number of half-lives, where x is a positive integer, the amount of "C"-14 left would be 1/2^x. Turns out that this also works for x not being an integer (but x still has to be positive).

So now we want to solve

1/2^x = 8%

Which is

x = log_2(1/(8%))

~~ 3.64

In terms of number of years, it would be

x * (5700 "years") = 3.64 * (5700 "years")

~~ 21000 "years"