In the figure, $△ABC$ is similar to $△ADE$. Point $B$ is on $\overline{AD}$ and point $C$ is on $\overline{AE}$. If $AB=5$, $BD=3$, and $BC=10$, what is the length of $\overline{DE}$?

(Note: Figure not provided, but implied by description of points and similarity)