Ray of light strikes the mirror at an angle of 60^o.

⇒ It will make an angle of 300 (90⁰ – 60⁰) with the normal.

∴ Angle of incidence = 30⁰.

Now, By laws of refraction;

Angle of incidence is 60^o

Refractive index of glass slab is 1.5

Putting the value in the above equation, we get

On solving the above equation, we get

Angle of refraction, r= 35.26^o

Thus the angel of refraction is 35.26^o from the normal.