30. Solving a chemistry problem

2. To determine titanium in steel, its weight of 0.250 g was dissolved, diluted to 100 ml. Reagents (H2O2) were added to 25 ml of the obtained solution and the volume was adjusted to 50 ml. To the second portion of 25 ml was added 0.22 mg of titanium, reagents and brought the volume to 50 ml. Photometrically in a cuvette with l= 1.0 cm Optical density of the first solution was equal to 0.22, and the second 0.50. What is the concentration of titanium in steel?