Answer
The fraction of the total area used for reserved seating is $\frac{17}{40}$.
Work Step by Step
Since the total area devoted to seating of fans and guests is $\frac{4}{5}$ and $\frac{3}{8}$ is used for general admission seating, we simply need to subtract both fractions to find out the ratio for reserved seating.
$\frac{4}{5} - \frac{3}{8} = \frac{ 4 \cdot 8}{5 \cdot 8} - \frac{3 \cdot 5}{8 \cdot 5} = \frac{32}{40}-\frac{15}{40} = \frac{32 – 15}{40} = \frac{17}{40}$.
