(i) The work done against friction is calculated using the formula:

\(\text{Work done against friction} = F \times d\)

where \(F = 40 \text{ N}\) and \(d = 36 \text{ m}\).

\(\text{Work done against friction} = 40 \times 36 = 1440 \text{ J}\)

(ii) The change in gravitational potential energy (PE) is given by:

\(\Delta PE = mgh\)

where \(m = 25 \text{ kg}\), \(g = 9.8 \text{ m/s}^2\), and \(h = 36 \sin 20^{\circ}\).

\(\Delta PE = 25 \times 9.8 \times 36 \times \sin 20^{\circ} \approx 3080 \text{ J}\)

(iii) The work done by the pulling force is the sum of the work done against friction and the change in gravitational potential energy:

\(\text{Work done by pulling force} = 1440 + 3080 = 4520 \text{ J}\)