power 4dLive 4D Results for Magnum 4D, Sports ToTo, DaMaCai 1+3D, Sabah 4D, CashSweep 4D, Sandakan 4D & SingaporeA convex lens of power 4D is kept in contact with a concave lens of power 3D, the effective power of combination will be . View Solution; The power of a concave lens is 10 D and that of a