17. Solving a chemistry problem

158. A sample of steel with mass m (g) was dissolved in a flask with a capacity of 50.0 ml. Two samples of 20.0 ml each were placed in flasks with a capacity of 50.0 ml. A solution containing 0.003000 g of vanadium was added to one flask. Hydrogen peroxide was added to both flasks and brought to the mark. Calculate the mass fraction (%) of vanadium in steel, if the following optical densities Ax and Ax+st were obtained during photometry of solutions:
Option 158
m, g 0.7468
Ah 0.250
Ax+st 0.530