For a good quality portland cement the ratio of CaO : SiO2+Al2O3+Fe2O3 must be

For good quality cementa) ratio of Silica (SiO2) to Alumina (Al2O3 )is between 2.5 and 4b)ratio  of lime (CaO ) to the total of SiO2 ,Al2O3 and Fe2O3 is close to 2