Inverses of Exponential Functions Practice Test

A cooling model is $f(t)=80\left(\dfrac34\right)^t$, where $t$ is minutes. Using the inverse, solve for $t$ when $f(t)=45$.

A population model is $f(t)=250\cdot 4^t$, where $t$ is years. Using the inverse, solve for $t$ when $f(t)=16000$.