Answer
$16.6\ mph$
Work Step by Step
The tire moves $2\pi\times215=430\pi$ radians per minute, thus $\omega=1360\pi\ rad/min$ and the linear speed is $v=r\omega=13\times430\pi=5590\pi\ in/min=5590\pi\times\frac{60}{12\times5280}\ mi/hr\approx16.6\ mph$
