In two cylindrical columns C1 and C2, both of the same height and, respectively, of diameters d and 2d, connected by a pipe of negligible volume at its bottom, are spilled four non-miscible liquids La, Lb, Lc and Ld. A balance is achieved for the system with La at the bottom of both columns, Lb over La in column C1, Lc over La and Ld over Lc in column C2. In this equilibrium position, the free surfaces of Lb and Ld are at the same height, and the contact surface of the liquid La with the other liquids is lower in column C1 than in column C2. The La liquid has a higher density than the other…