The mass (in grams) of a radioactive substance changes according to

MATHEMATICS · Subjective · AP · Calculus AB · Differential Equations · Differential Equations

Problem

The mass

M

(in grams) of a radioactive substance changes according to

\dfrac{dM}{dt}=-0.04M

, where

t

is in days. If

M=120\,\text{g}

when

t=0

, calculate the mass remaining after 15 days.