An 18 V battery is connected to a network of four capacitors. The first two capacitors (C1 = 120 F and C2 = 200 F) are in series with each other, and the other two capacitors (C3 = 350 F and C4 = 520 F) are in parallel only with each other. After a long while has passed, how much energy E has been supplied to the capacitors by the battery?

For the limits check, investigate what happens to Eif the capacitance of the first capacitor drops to zero.