# science

posted by .

how old is a mammoth's tusk if there is only 25 percent C-14 remaining in the sample?

a.5700 years
b.11400 years
c.17100 years
d.22800 years

• science -

Half disappeared in one half-life.
Half that remaining disappeared in the next half-life.

• science -

..what does that mean?

• science -

Knowing the half-life of C-14 would allow you to take twice the half-life.

From searching the Internet under "C-14 half life", I found that the half-life of Carbon 14 is 5730 years.

This should help a little more. Thanks for asking.

• science -

b.11400 years

• Chemistry -

B. 11400 years

• science -

5700

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