Answer
$n=\frac{9}{20}$
Work Step by Step
$\frac{\frac{1}{3}}{\frac{3}{8}}=\frac{\frac{2}{5}}{n}$ $\longrightarrow$ cross multiply to solve for n
$\frac{1}{3}n=\frac{3}{8}\times\frac{2}{5}$$\longrightarrow$multiply
$\frac{1}{3}n=\frac{6}{40}$$\longrightarrow$multiplication property of equality
$\frac{1}{3}n\times3=\frac{6}{40}\times3$$\longrightarrow$ divide
$n=\frac{18}{40}$$\longrightarrow$simplify
$n=\frac{18\div2}{40\div2}$
$n=\frac{9}{20}$