Answer:
Increase 9 times
Explanation:
We have Newton formula for attraction force between 2 objects with mass and a distance between them:
[tex]F_G = G\frac{M_1M_2}{R^2}[/tex]
where [tex]G =6.67408 \times 10^{-11} m^3/kgs^2[/tex] is the gravitational constant. [tex]M_1, M_2[/tex] is the masses of the 2 objects. and R is the distance between them.
Since the force is inversely proportional to the distance squared, if it is reduced by 3 times, the gravitational force between them would increase by [tex]3^2 = 9[/tex] times
