80. Solving a chemistry problem

2. Calculate the concentration of Fe3 and the molar light absorption coefficient of the colored solution (with sulfosalicylic acid), analyzed by spectrophotometry at λ=416 nm in a cuvette with l=2 cm, if the optical density of the standard solution with a concentration of 2.00 mg/l is 0.285, and standard solution with a concentration of 4.00 mg / l - 0.56. The optical density of the test solution was 0.45.