Carbon-14 has a half-life of 5730 years In a plant fossil you find that the 14 C has decayed to 1/8 of the original amount how long ago was this plant

Answer 1

1/8=e^-.693t/5630

4730 ln(1/8)=-.693t

solve for t

another way:
1/8=(1/2)^t

t=3 halflives