Object a has a mass of 12 g and a density of 3 g/cm3. Object b has a mass of 12 g and a density of 5 g/cm3. Which object has a greater volume and by how much? object a, by 2. 6 cubic centimeters object a, by 1. 6 cubic centimeters object b, by 2. 6 cubic centimeters object b, by 1. 6 cubic centimeters.