9c

In order to solve this problem, use the following equations and steps shown: $\begin{aligned} c_{i n v} = n \cdot c_{l i g h t} + c_{i n s t} \\ c_{i n v} = 197, 000 e u r o s \\ Δ t = \frac{c_{i n v}}{c_{s a v e}} \\ Δ t = \frac{197, 000}{24, 842} \\ Δ t = 7.93011834796 y e a r s \end{aligned}$