Question

The decay of 277 mg of an isotope is described by the function A(t)= 277e-0.019t, where t is time in years. Find the amount left after 64 years. Round your answer to the nearest mg.

Answer 1

The decay of 277 mg of an isotope is described by the function
A(t)= 277e-0.019t,
where t is time in years.
To find the amount left after 64 years,

We substitute t = 64 in the expression.
A(t=64)= 277e-0.019(64)
or A(t=64) = 277 * e-1.216
                 = 277 * 0.29
                 = 82 mg