Gravitational field, density and mass.

[lostie100]

A satellite orbits a planet. The gravitational field strength at the radius of the orbit is 12 N/kg. What will the gravitational field strength at the position of the satellite be if
- The planet's density is doubled?
- The satellite's mass is doubled?

I just don't understand their relationship. Any help is appreciated =)

 

[WarPhalange]

Do you know the formula for gravitational force?

 

[lostie100]

F = Gm1m2/r^2
but doubling the mass doesn't double the force.