Three conducting bodies A(solid sphere), B(spherical shell) and C(hollow sphere with thickness R) are arranged as shown in the figure. A charge q is given to the inner sphere. When $S_1,S_2$ both are open, capacity of system is $C_1$ and when $S_1,$ is closed but $S_2$ is open capacity is $C_2,$ then $(C_2-C_1)=\frac{X\pi {\epsilon }_{0}R}{55}.$ When $S_2$ is closed but $S_1$ is opened capacity is $C_3$ and when both $S_1$ and $S_2$ are closed capacity is $C_4$ then $(C_4-C_3)=\frac{Y\pi {\epsilon }_{0}R}{3}.$