AP and TS EAMCET Medical Model Paper 4

A parallel plate capacitor with air between the plates has a capacitance of 9 PF. The separation between its plate is d. The space between the plates is now filled with two dielectrics. One of the dielectric has dielectric costant K1 = 3 and thickness d/3 while the other one has dielectric constant K2 = 6 and thickness 2d/3 Capacitance of capacitor will be