Question

Carbon-14 tests are often performed to determine the age of an organism that died a long time ago. Carbon-14 has a half-life of 5730 years. If a turtle shell is found and tested to have 65% of its original carbon-14, how old is it

Answer 1

2006 years old.

Explanation:

If it had 50% of its carbon-14 it would be 5730 years old.

Since it has 65% left it is younger than 5730 years.

So it is (1 - 0.65) * 5730

= 2005.5 years old.