The quantity at time t is given by the formula Q(t)=Q(0)*e^kt where Q(0) is the initial amount.

Since the half life is 3000 years, we can write:

0.5Q(0)=Q(0)*e^3000k which means that:

0.5=e^3000k

ln0.5=lne^3000k

ln0.5=3000k

ln0.5/3000=k

Thus, after finding k we can calculate:

Q(t=5000)=100*e^{5000*ln0.5/3000}

=100*e^5*ln0.5/3

=100*e^-1.155=31.49