Logarithmic Functions Practice Test

A radioactive isotope has half-life $8$ days, modeled by $A(t)=A_0\left(\tfrac12\right)^{t/8}$. Determine $t$ when $A(t)=0.20A_0$ using logarithms.​

A city’s population is $P(t)=150{,}000(1.03)^t$. Based on the scenario, how would you use logarithms to solve for $t$ when $P(t)=200{,}000$?