58. Solving a chemistry problem

58. Calculate the mass fraction of CaCO3 and MgCO3 in limestone, if after dissolving 1.00 g of it, 100 ml of a solution were obtained, for titration of 20 ml of which, 19.25 ml of 0.05140 M EDTA solution was spent to determine the amount of Ca and Mg, and for titration Ca in a separate sample (20 ml), 6.25 ml of the same EDTA solution was used.