Question

angle blw mirror and reflected ray for a ray is 30degrees then, deviation suffered by the incident ray is

Answer 1

The angle of deviation is the angle between the incident ray to the reflected ray. 
If we figure it in mind this angle 180-2(incident angle)

the angle of reflection =90-{angle bw mirror and reflected surface}=angle of incidence.
==>>90-30=60

So D=180-2x60=180-120=60
     
     D=60degrees

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Answer 2

answer is 60 degree.