82. Solving a chemistry problem

2) a sample of steel weighing 0.6150 g was dissolved in a flask with a capacity of 50.00 ml. Aliquots of 20.00 ml each were taken into two 50.00 ml volumetric flasks. A solution containing 0.001000 g of Ti was added to one flask. Hydrogen peroxide solution was placed in both flasks and the solutions were made up to the mark.
Calculate the mass fraction (%) of titanium in steel if Ax=0.250; Ax+st=0.470.