Half-life and Carbon-14??

Question

I know that the half life of Carbon-14 is 5730 years,
but what would be the age of a fossil containing 1/16 the amount of Carbon-14?
Im puzzled...
any help would be appreciated

Answer 1

Remember that a half life is the amount of time required for half of the remaining material to decay.

If 1/16 remains, we can determine how many half-lives have taken place.

After 1 half-life, 1/2 of the material would remain.
After 2 half-lives, 1/2 of 1/2, or 1/4 of the material would remain.
After 3, 1/2 of 1/4 or 1/8 would remain.
After 4, 1/2 of 1/8 or 1/16 would remain.

So, 4 half-lives have occured.

Each half life is 5730 years, so 4 half-lives would be 4*5730 years = 22,920 years.