Loss of purchasing power of the euro

Statement

If the euro loses purchasing power at $2\%$ per year, what will $1\ \text{€}$ be worth in real terms $20$ years from now?

Solution

$D=1\cdot(0{.}98)^{20}$. $D=(0{.}98)^{20}=0{.}667587\approx\boxed{0{.}6676\ \text{€}}\ (\approx 67\ \text{cents}).$