The forces of attraction acting between two bodies is :

1. directly proportional to the product of their masses
2. directly proportional to the square of the distance between them
3. inversely proportional to the square of the distance between them
4. both (a) and (c)

both (a) and (c)

Reason — According to Newton, the force of attraction acting between two bodies is :

1. directly proportional to the product of their masses.
2. inversely proportional to the square of the distance between them.

Hence, we get, F = $\dfrac{Gm$1m2}{r^2}