Four capacitors are connected as shown. C1 = 2.00 JF, C2 +4.00 UF, C3 = 3.00 uF, and C4 = 6.00 uF. A 12.0 V battery is connected across the combination (from a to b). CI C3 b a C2 C4 a) What is the equivalent capacitance of the combination? (Input the numerical value only, in units of microfarads.)