The math ratio that represents efficiency is option D). Fo x do / Fi x di.In this ratio:Fi represents the input force or input quantity.di represents the input distance or input time.Fo represents the output force or output quantity.do represents the output distance or output time.Efficiency is typically calculated by comparing the output to the input. In the case of mechanical systems, it is often measured as the ratio of output work or energy to input work or energy.Therefore, the ratio Fo x do / Fi x di represents the output work or energy divided by the input work or energy, which is commonly used to determine efficiency in various contexts.