The answer is:
Total used energy is the energy released by the hydrolysis of one mole of ATP and it is 30.7 kJ. Â
Total possible energy (used pus released as a heat) is 2870 kJ.
So, we calculate total used/total possible=30.7/2870=0.01069 or 0.017. Expressed in percentage: 1.07% energy is used.