What is the significance of the fact that the droplets carried different charges?

The charges on a droplet can be used to represent the number of electrons carried by this droplet.
In other words:
a droplet having a charge of 1.60 x 10^-19  has 1.60 x 10^-19  electrons while a droplet having a charge of 3.15 x 10^-19  has 3.15 x 10^-19  electrons.

From the observations:
The fact that the droplets carried different charges signifies the fact the different droplets carried different numbers of electrons

The answer is 3,5g co