Energy efficiency is linked to an element's ability to create energy in relation to the level of energy consumption. Typically, systems with this feature can keep up and consume fewer resources. In the case reported in the question, Pria's radio produces 80 units of useful energy for every 100 units of electricity used, so to know in percentage what is the efficiency of Pria's radio, we only need to multiply the 80 units of useful energy of Pria's radio, by 100% and divide the result by the 100 units of electricity used. This calculation is made as follows:
