Question

The gravitational force between two objects (mass1 = 10kg, mass2 = 6kg) is measured when the objects are 12 centimeters apart. If the distance between them is increased to 36 centimeters, how does the new gravitational attraction compare to the first one that was measured? A. The new gravitational force is 3 times larger than the old one B. The new gravitational force is 9 times larger than the old one C. The new gravitational force is 3 times smaller than the old one D. The new gravitational force is 9 times smaller than the old one

Answer 1

Since the new distance is 3 times the old distance,
the new force is (1/3²) = 1/9th of the old force.

That's kind-of Choice-D, but I really don't like the way choice-D is worded.
"9 times smaller" is really pretty meaningless.