Is it possible to make calculations of the net gain of ATP?

Is it possible to make calculations of the net gain of ATP? Correct Answer Possible only theoretically

Yes, it is possible to make calculations of the net gain of the ATP that is formed in the respiratory pathway by the oxidation of some suitable respiratory substrates but this can remain only a theoretical exercise as the real amount of energy released in the cell may vary.
Bissoy MCQ

Related Questions

Statement I Two ATP molecules are produced during anaerobic respiration.
Statement II Glucose is converted into pyruvic acid through a series of reaction with a net gain of 2 ATP molecules.