How much cement and sand to cover 15 square meters?

To cover 15 square meters with a cement-sand mixture, the amount needed depends on the thickness of the layer you plan to apply. For a standard 1 cm thick layer, you would require approximately 0.15 cubic meters of the mixture. A common ratio for a cement-sand mix is 1:3, which means for every part of cement, you would need three parts of sand. Thus, you would need about 37.5 kg of cement and 112.5 kg of sand for this coverage, assuming a density of about 1440 kg/m³ for the mixture.