111. Solving a chemistry problem

11(2). A sample of steel weighing m g was dissolved in a flask with a capacity of 50.00 ml. Two samples of 20.00 ml each were placed in flasks with a capacity of 50 ml. A solution containing 0.003000 g of vanadium was added to one flask. Hydrogen peroxide was added to both flasks and made up to the mark with water.
Calculate the mass fraction (%) of vanadium in steel, if the following optical densities Ax and Ax + st were obtained during photometry of solutions.
Option 1 2 3 4
m, g 0.5000 0.6572 0.7468 0.9580
Ax 0.200 0.230 0.250 0.280
Ax+st 0.480 0.510 0.530 0.560
Answer: 1) 1.07%; 2) 0.94%; 3) 0.90%; 4) 0.78%