First, resolve the forces acting on the block. The gravitational force component parallel to the plane is given by:

\(F_g = mg \sin \theta = 20 \times 9.8 \times \sin 10^\circ\)

\(F_g = 34.2 \text{ N}\)

The normal force \(R\) is given by:

\(R = mg \cos \theta = 20 \times 9.8 \times \cos 10^\circ\)

\(R = 193.2 \text{ N}\)

The frictional force \(F_f\) is:

\(F_f = \mu R = 0.32 \times 193.2 = 61.8 \text{ N}\)

(i) When the force acts up the plane, the equation of motion is:

\(P = F_f + F_g = 61.8 + 34.2 = 96 \text{ N}\)

Thus, the least magnitude of the force is 97.8 N.

(ii) When the force acts down the plane, the equation of motion is:

\(P = F_f - F_g = 61.8 - 34.2 = 27.6 \text{ N}\)

Thus, the least magnitude of the force is 28.3 N.