A light ray is incident, at an incident angle θ_1, on the system of two plane mirrors M_1 and M_2 having an inclination angle 75° between them (as…

A light ray is incident, at an incident angle $\displaystyle \theta_1$, on the system of two plane mirrors $\displaystyle \mathrm{M}_1$ and $\displaystyle \mathrm{M}_2$ having an inclination angle $\displaystyle 75$° between them (as shown in figure). After reflecting from mirror $\displaystyle \mathrm{M}_1$ it gets reflected back by the mirror $\displaystyle \mathrm{M}_2$ with an angle of reflection $\displaystyle 30$°. The total deviation of the ray will be \_\_\_\_ degree.