Frictionless Incline

On a frictionless ramp only gravity acts along the slope, so the mass cancels:

$$a = g\sin\theta$$

No friction: only mg and N act, and the acceleration points down the slope.

On a $30^\circ$ ramp $a = 4.9\ \mathrm{m/s^2}$, for every mass. A rope pulling up the slope with $F$ adds a term: $F - mg\sin\theta = ma$.