Calculate the relative formula mass of Iron(III) Oxide (Fe2O3)

Iron (III) / Fe3+ Mr = 56Oxygen / O Mr = 16
Iron (III) Oxide formula = Fe2O3
2x Iron (III) = 56 * 2 = 1123x Oxygen = 16 * 3 = 48
48 + 112 = 160
Fe2O3 relative formula mass = 160