What calculation is represented by 'КПД = Аn / A · 100%'?

This formula calculates the efficiency (КПД) of the inclined plane. 'Аn' (or 'Aпoлезн' in the context of the table header) represents the useful work done, and 'A' (or 'Aзатр') represents the total work input. Multiplying by 100% gives the efficiency as a percentage.