100 kg of CaCO3 gives 56 kg of CaO.
Since lime stone is 95% pure; amount of CaCO3 present in 200 kg of impure sample = 190 kg CaCO3 100 kg of CaCO3 gives 56 kg of CaO
1 kg of CaCO3 gives 56/100 kg of CaO
190 kg of CaCO3 give 56/100× 190 = 106.4 kg of CaO.