Question

As the distance between two objects increases the force of gravity between them is

Answer 1

The force of gravity is proportional to 1/r^2, where r is the radius (distance) between the objects.
So if the force was originally$\frac{1}{r^2}$, doubling the distance between them would make the new force $\frac{1}{(2r)^2} = \frac{1}{4r^2} = (\frac{1}{4}) \frac{1}{r^2}$