Suppose the market for cigarettes is characterized by the following information : Qd= 70-5P (demand) Qs = 3P-10 (Supply) Suppose the government impose a sales tax of $2 per unit. Calculate the Dead-Weight-Loss due to the sales tax. (Note : P= Price per unit; Qd= thousands of units demanded; Qs = thousands of units Supplied) Solution Let us first find the equilibrium price an quantity for the market. The demand and supply function for the cigarettes is given as, Qd = 70.