Answer
The function represents exponential decay and the rate of decay is $40\%$.
Work Step by Step
The given function is
$\Rightarrow f(t)=80(\frac{3}{5})^t$
$\Rightarrow f(t)=80(0.6)^t$
$\Rightarrow f(t)=80(1-0.4)^t$
The function is of the form
$y=a(1-r)^t$, where $1-r<1$.
So, it represents exponential decay.
Decay factor is
$\Rightarrow 1-r=0.6$
Add $r-0.6$ to each side.
$\Rightarrow 1-r+r-0.6=0.6+r-0.6$
Simplify.
$\Rightarrow 0.4=r$
$\Rightarrow r=40\%$.
Hence, the function represents exponential decay and the rate of decay is $40\%$.
