From information given, there are two forces in action, the vertical and the horizontal. We first need to calculate separately work done by these two forces, then determine the efficiency. Work = Force × distance work(a) → 600N × 2m = 1,200 Nm work(b) → 300N × 5m = 1,500 Nm Efficiency = work(a) / work (b) × 100 Efficiency = 1200 / 1500 × 100 Efficiency = 0.8 × 100 Efficiency = 80% Therefore the efficiency of the ramp is 80%