Two buckets of paint each have a mass of 9 kg. If the gravitational force between them is 6.0x10 to the power of minus 10, how far apart are they?

Gravitational force = (gravity x mass1x mass2)/distance^2
6.0x10^-10 = (6.67x10^-11 x 9 x 9)/d^2
D = sqrt(6.0x10^-10/6.67x10^-11 x81)
D = 3.0 m
The answer is B.3.0 m