Answer:
ITS 21
Step-by-step explanation:
<span>* carbon-14 levels in a sample are undetectable after approximately nine half-lives.
Nine half-lives pf carbon 14 is 51,570 years.
Source:
https://en.wikipedia.org/wiki/Radiocarbon_dating
</span>
Personally, I would recommend reading this as a fraction, and splitting up mantissa from the power of 10. (Mantissa refers to the number 1.23 in
.)

Now just reduce each fraction:


So

since
.
Answer:
none of the above
Step-by-step explanation:
none of the are correct
I think the answer to your question is -2