Single discount: D1=40% Successive discounts: D2=25% and 15% Effective Discount for successive discounts: Deff =D2a+D2b−(D2a×D2b) Where, D2a=25% and D2b=15% Calculation: Effective discount for successive discounts: Deff=25%+15%−(25%×15%) ⇒Deff=0.25+0.15−(0.25×0.15) ⇒Deff=0.25+0.15−0.0375 ⇒Deff=0.3625 or 36.25% Difference between the single discount and the effective successive discount: Difference =40%−36.25% ⇒ Difference = 3.75\%