This is because calculating clams can be incredibly complex if based on an itemised bill. Formulae allow a relatively straightforward way of calculating overheads and profit which negates the need for an itemised breakdown of every element involved.
This is because calculating clams can be incredibly complex if based on an itemised bill. Formulae allow a relatively straightforward way of calculating overheads and profit which negates the need for an itemised breakdown of every element involved.