39. Solving a chemistry problem

4. A 0.5 g sample of metal was dissolved, and after oxidation of the manganese contained in it to MnO4-, 100 ml of a solution were obtained. A 0.01 N solution of potassium permanganate was used as a standard. When compared in a colorimeter, the color intensity of the standard and test solutions turned out to be equal with a layer thickness of 5 and 8.49 cm, respectively. Determine the manganese content in the metal in%