Question

The amount of carbon-14 still present in a sample after t years is given by the function
where C0 is the initial amount. Estimate the age of a sample of wood discovered by an archeologist if the carbon level in the sample is only 18% of its original carbon-14 level. FORMULA UPLOADED

Answer 1

"18% of the original carbon level" means that \[C(t) = (.18)C_0\]
putting this in your equation you get\[(.18)C_0 = C_0 e ^{-.00012t}\]
You can divide out the initial value and solve for t\[(.18) = e ^{-.00012t} \Longrightarrow \ln(.18) = -.00012t \Longrightarrow t = \ln(.18)/(-.00012) \]

Answer 2

what did you get?

Answer 3

Unfortunately I don't own a scientific calculator, so I can't compute natural logs, I'm sry.