1. The problem statement, all variables and given/known data A Mg-Al alloy has a mass of 0.263 g and a density of 2.40 g/cm3. The density of pure Mg = 1.74 g/cm3 and for pure Al = 2.70 g/cm3. Calculate the % Mg in the alloy. 2. Relevant equations D=M/V 3. The attempt at a solution Well I'm not really sure where to do. I solved for the volume of the alloy, then tried to use it to determine the mass of the Mg. Once there I divided by the total mass and multiplied by 100 to get the wrong answer. How can I go about getting the mass of Mg in the alloy?