How does the force of gravitation between two objects change when the distance between them is reduced to half ?

Explanation

By universal law of gravitation, the gravitational force between two objects is inversely proportional to the square of the distance them.
`F pro (4)/((r//2)^(2))`
or `F prop (4)/(r^(2))`
so `(F.)/(F) prop ((4)/(r^(2)))/((1)/(r^(2)))`
`(F.)/(F) = 4`
Thus, the gravitational force will increase four times when the distance is reduced to half.