Iron (iii) oxide(s) is heated in excess carbon monoxide(g) to form iron(s) and carbon dioxide(g). If the perc?

Iron (iii) oxide(s) is heated in excess carbon monoxide(g) to form iron(s) and carbon dioxide(g). If the percent yield of iron was 83.0% and the actual yield was 9.87 g, how much iron (iii) oxide was used?