111. Solving a chemistry problem

19. When determining vanadium by the method of additions, a sample of steel 0.5036 g was transferred into a solution and its volume was brought to 50.0 ml. Aliquots of the solution of 20.0 ml each were taken into two 50 ml volumetric flasks; a standard solution containing 0.003 g of vanadium was added to one of these flasks, then hydrogen peroxide was added to both flasks. The solutions in the flasks were brought to the mark, photometrically and received: Dx=0.20 and Dxst=0.48. Calculate the percentage of vanadium and steel.