Question

how does the gravitational force between the two bodies change if the distance between them is tripled

Answer 1

G=M*m/d2. Which means the square of the distance is inversely proportional to the force. If distance is multiplied by 3, the d2=9 and force will be 1/9.

Answer 2

Gravitational force between two objects is GMm/r square

Is the distance i.e r is tripled then it will be GMm/(3r) the whole square

i.e GMm/9r square

Hence it will be 1/9 the original force