Answer
$0^{\circ}$
Work Step by Step
To find the angle of the refracted ray, use Snell's law $$n_1sin\theta_1=n_2sin\theta_2$$ Since $\theta_1=0$ for the first refraction, $\theta_2$ will always equal zero. This process will always repeat through each substance. This means that the resultant angle will be zero degrees from the normal.
