131.Solving a chemistry problem

21 In the case of a nephelometric comparison of two hydrosols, a sol with an average particle radius of 100⋅10-9 m with a beam width of 8⋅10-3 m had the same illumination of the field of view in the eyepiece as the tested sol on which a beam of light was incident through a slit of width 27⋅10-3 m. Determine the radius of the sol particle.