Electric Potential Energy Practice Test

If the electrical potential energy between two equal charges quadruples, describe the change in the distance between the particles.

For the following:

e = 1.60 times $10^{-19}$

k = 8.99 times $10^{9}$

If a charge of magnitude +4e is being held in place 3 nm from a charge of -5e which is also being held in place. What is the potential energy of the system?