Hi

The Capacitance of big drop will be 20μF

EXPLANATION

We have,

Volume of  big drop = 64 times the volume of small drop

or 4/3 π.R3 =64 x 4/3 π.r3

Or  R = 4r

Now, we know that  the capacitance for a  solid spherical body is  directly proportion to radius of the solid sphere

Then,

Capacitance of big drop

= 4 x capacitance of   small drop

=4 x 5

=20μF

Thank you