Two equipotential surfaces surround a +1.38 10-8-C point charge. How far is the 179-V surface from the 67.5-V surface?

The question is incomplete, below is the complete question

"Two equipotential surfaces surround a +1.38*10^-8C point charge. How far is the 179-V surface from the 67.5-V surface? "

1.15m

Explanation:

From the formula connecting the charge, potential and the distance i.e

where q=charge, k=constant and r=distance between the points

the data given in the question are

We can express the distance from the charge to the equipotential surface as

for the second charge we have

The distance between the two surface is

Hence the distance is 1.15m

hypothesising or postulating

heat the gas and measure the pressure