#### Answer

$35n + 10$

#### Work Step by Step

The inscribed tiles cost 15 dollars each, and the plain tiles are 5 dollars each. The number of inscribed tiles there are is $2n$, and the number of plain tiles there are is $n+2$.
$15(2n) + 5(n+2)$
$30n + 5n + 10$
$\boxed{35n + 10}$