Given that the mass of the raindrop is

The acceleration due to gravity is g = 9.81 m/s^2
We have to find
(a) Magnitude of the gravitational force exerted on the raindrop by earth
(b)Magnitude of the gravitational force exerted on the earth by the raindrop
(a) The formula to calculate the magnitude of the gravitational force exerted on the raindrop by the earth is

Substituting the values, the gravitational force exerted on the raindrop by the earth is

(b) According to Newton's third law,
If F' is the gravitational force exerted on the earth by the raindrop, then

Here, the negative sign indicates that both forces act in opposite direction.
The gravitational force exerted on the earth by the raindrop is

And the magnitude of the gravitational force exerted on the earth by the raindrop is

Thus, the magnitude of both forces is equal.