Time to accrue a simple interest

Statement

For how many years must $3000\ \text{€}$ be invested at $4\%$ simple interest to yield $480\ \text{€}$ of interest?

Solution

From $I=C\,r\,t$ we get $t=\dfrac{I}{C\,r}$. $t=\frac{480}{3000\cdot 0{.}04}=\frac{480}{120}=\boxed{4\ \text{years}}.$