When you add up (20N down) and (10N up),
you get a sum of (10N down).
The mass of the object has no effect on the forces.
Now ... I see 5 points for the answer.
Where are the other 25 coming from ?
After my ythorough researching, the orbital velocity of the Earth compare to the Mercury is relative to each other. In addition, Mercury orbits the Sun and it is within the Earth's orbit as its lesser or inferior. The correct answer to the following given statement above is relative to each other.
