Electric potential due to a point charge is given by
[tex]V = \frac{kQ}{r}[/tex]
here we know that
Q = charge
r = distance from the charge
[tex]V = \frac{9*10^9* 2.2* 10^{-6}}{6.3}[/tex]
[tex]V = 3142.8 Volts[/tex]
now again by the same equation
[tex]V = \frac{kQ}{r}[/tex]
[tex]V = \frac{9*10^9* 2.2* 10^{-6}}{99}[/tex]
[tex]V = 200 Volts[/tex]