howt to solve problem no. 32

Q:The refractive index for the material of a 60 prism is1.5.then the angle of incidence for minimum deviation is nearly?

Hey kashif U can first find minimum deviation of a prism by using formula ü=[sin{(A+d) /2}]/sin (A/2).. Where d is the minimum deviation and u is its refractive index... Then U can use the concept that at min deviation angle of incidence is equal to angle of emergence.. So use the formula d=i+e-A... Since i=e.. Then u can find i... Hope U like it...