What is the efficiency formula expressed as a fraction?

The efficiency of a system is calculated by comparing the output work to the input work. In this context, efficiency is expressed as a fraction where the numerator represents the useful work produced by the system and the denominator represents the total work put into the system. Therefore, the correct representation of efficiency as a fraction is WORKout divided by WORKin.

This formula highlights how effectively a system converts the energy supplied into useful work. If the output work is high relative to the input work, the efficiency is high, indicating that the system is effective in its operation. Conversely, if the output is low compared to the input, the efficiency is correspondingly low, revealing losses due to factors such as friction or heat.

Other options may relate to different aspects of work or power, but they do not accurately reflect the general formula for efficiency in terms of work input and output.