A beam of light with red and blue components of wavelengths 670 nm and 425 nm, respectively,

Question:

A beam of light with red and blue components of wavelengths 670 nm and 425 nm, respectively, strikes a slab of fused quartz at an incident angle of 30o. On refraction, the different components are separated by an angle of 0.001 31 rad. If the index of refraction of the red light is 1.4925, what is the index of refraction of the blue light?