Carbon-14 has the half-life of about 5400 years.
(a) Determine the function which provides the amount, A, of carbon-14 in an object after t years. (Use variable to represent initial amount.)
A(t) = ae -0.000123861t
(b) Leaf is found that has 25% of carbon-14 it originally had. About how old is it? (Round the answer to the nearest year.)