(1×10^-5)/(1.6×10^-19)= 6.25×10^13 electrons(ans)
Notice that the charge of a sphere is very larger than charge of electron obviously, so each electron on the sphere is made of 1.6×10^-19 charge, so you found how many of these charges are required for you to make a charge of 1×10^-5
for Example: your electron has charge 2 on it
and the sphere has charge 200 on it, then the number of electrons that make up that charge will be
200/2 = 100 electrons.
