Marginal revenue is the addition to total revenue by selling one more unit of the commodity.
Algebraically it is the total revenue earned by selling ‘n’ units of the commodity instead of n-1. Thus,
MRn = TRn – TRn-1; where MRn = Marginal revenue of the nth unit
TRn = Total revenue of n units
TRn-1 = Total revenue of n-1 units
