Answer
$0.41^{\circ}$.
Work Step by Step
Use Snell’s Law, where the angles are measured from the normal to the interface. First for the red light.
$$n_a sin\theta_a= n_b sin\theta_b$$
$$\theta_b=sin^{-1}(\frac{n_a}{n_b}sin\theta_1) $$
$$=sin^{-1}(\frac{1.00}{2.41}sin53.5^{\circ}) =19.48^{\circ}$$
Next for the violet light.
$$n_a sin\theta_a= n_b sin\theta_b$$
$$\theta_b=sin^{-1}(\frac{n_a}{n_b}sin\theta_1) $$
$$=sin^{-1}(\frac{1.00}{2.46}sin53.5^{\circ}) =19.07^{\circ}$$
From these two values, calculate the final angle between the two initially parallel rays.
$$\Delta \theta=19.48^{\circ}-19.07^{\circ}=0.41^{\circ}$$