A colloid I think. Don’t hold it against me if I’m wrong my dude.
The moon dosent revolve around earth as the earth rotates the moon stays in the same place
Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
As we know that the gravitational force is given as

so we will have to find the ratio of force on two planets due to star
so here we have



Part b)
Orbital speed is given as

so the ratio of two orbital speed is given as


Part c)
Time period is given as

so the ratio of two time period is given as


