Time to quadruple with continuous compounding

Statement

In how many years does a capital quadruple at $8\%$ with continuous compounding?

Solution

$e^{0{.}08\,t}=4\Rightarrow t=\dfrac{\ln 4}{0{.}08}=\dfrac{1{.}386294}{0{.}08}\approx\boxed{17{.}33\ \text{years}}.$