Correct Answer - `(a) 60^(@) (b) 120^(@),60^(@) (c) 5`
(a) Angle of reflection at the second plane mirror =`60^(@)`
(b) Angle of deviatioin at `M_(1)=180-2i`
`" "=180-2(30)`
`" "=120^(@)`
Angle of deviation at `M_(2)=180-2i`
`" "=180-2(60)`
`" "=180-120=60^(@)`
(c)
Number of images `=(360)/(theta)-1=(360)/(60)-1=5`