Electric Forces

[punjabi_monster]

Two point charged objects produce an electric force on each other of 6.20 * 10^-2 N. What is the electric force if the distance between increases three times?

I understand that this formula can be used, Fe=(kq1q2)/R^2, but how can you determine K and R from this formula. Any help would be appreciated.

[Tide]

It's simple ratios and proportions. Write out the two forces for each case then divide one equation by the other - the K will cancel out and so will the R if you use the information provided.