The Capacitance of big drop will be 20μF
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