At y = 1 cm, y = 3 cm y = 9 cm, y = 27 cm ... and so on, an infinite number of charges equal to 4C are placed.  At  x = 1 cm, x = 2 cm, x = 4 cm, x = 8 cm .... and so on, an infinite number of charges equal to – 4C are placed.  Find the electric potential at origin in volts. (K=14πε0 )