Forces and equilibrium — practice question

A particle with mass $m\text{ kg}$ is at rest on a rough plane that is inclined at $30^\circ$ to the horizontal. A force of magnitude $10\text{ N}$ acting on the particle up a line of greatest slope of the plane is just enough to prevent the particle from sliding down the plane. When a force of $75\text{ N}$ acts on the particle up a line of greatest slope of the plane, the particle is just about to slide up the plane.