Food-cost percentage is called net profit

A fictional restaurant sells one dish for twelve currency units and assigns three currency units of ingredient cost to each portion. The supplied example says nothing about wages, rent, energy, waste beyond that ingredient allocation, financing or taxes. A colleague calculates twenty-five percent and labels the remainder guaranteed net profit. Another preserves the useful ingredient-cost ratio but identifies the additional costs and assumptions needed for a broader conclusion. This written exercise changes no menu or price. It asks for the supplied food-cost percentage, distinguishes markup and contribution from net profit and explains why a correct arithmetic ratio cannot establish every commercial outcome or customer demand at the proposed price.