Answer
$$ R\approx \$1200/year$$
Work Step by Step
For a large number of years, we have
$$ PV\approx\frac{R}{r}$$
Then for $ PV=20000 ,\ \ \ r=0.06 $,
\begin{align*}
PV&\approx\frac{R}{r}\\
20000& \approx\frac{R}{0.06}
\end{align*}
Hence $$ R\approx \$1200$$
