Gravitational Force Practice Test

Masses $m$ and $2m$ are separated by $r$ and attract with force $F$. The $2m$ mass is replaced by $6m$ while $r$ stays the same. What is the new force magnitude?

Two small spheres interact gravitationally: sphere A has mass $2m$ and sphere B has mass $m$. Their center-to-center distance increases from $r$ to $2r$. How does the gravitational force magnitude change?