In order to calculate the amount left after 3 years, we can use the following equation for exponential decay or growth:
[tex]P=P_0\cdot(1+i)^t[/tex]Where P is the final amount after t years, P0 is the initial amount and i is the growth or decay rate per year.
In this case, let's use P0 = 64, i = -0.5 (it decays half of the amount in a year) and t = 3, so we have:
[tex]\begin{gathered} P=64(1-0.5)^3 \\ P=64\cdot0.5^3 \\ P=64\cdot0.125 \\ P=8 \end{gathered}[/tex]So there will be left 8 grams after 3 years.
