Accumulated value of a loan

Statement

A craftsman borrows $1200\ \text{€}$ for $10$ months at $12\%$ simple interest. What amount must he repay?

Solution

The accumulated value is $M = C\,(1 + r\,t)$, with $t = \dfrac{10}{12}$. $M = 1200\left(1 + 0{.}12\cdot \frac{10}{12}\right) = 1200\cdot 1{.}1 = \boxed{1320\ \text{€}}.$