The gravitational force F between two bodies of masses M and m, separated by a distance R, has a magnitude of
F = GMm/R ²
We're given that
F₁ = Gm₁m₂/r ²
and
F₂ = G (2m₁) (4m₂)/(2r )²
Now,
F₂ = G (2m₁) (4m₂)/(2r )²
F₂ = 8/4 Gm₁m₂/r ²
F₂ = 2 Gm₁m₂/r ²
F₂ = 2 F₁
so n = 2.
