Need help on a very simple 8th grade conscept.

[rilkesorpheus]

Two stars move towards each other due to the forge of gravitation. Star 1 has twice the mass of star 2. Which if either exerts a greater gravitational force? Why?

 

[Mindscrape]

What are your thoughts? If I drop a pencil does the planet exert the same force on the pencil as the pencil does on the planet?