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The marked price of a cooker is same at four shops I, II, III and IV. Shop I allows two successive discounts of 23% and 92%, shop II allows successive discounts of 88% and 47%, shop III allows successive discounts of 11% and 28% and shop IV allows successive discounts of 63%, 76% and 86% on the marked price of the cooker. Which shop is selling the cooker at the lowest price? 3370
III
IV
II
I Question ID : 441009536895 Option 1 ID : 4410092102977 Option 2 ID : 4410092102976 Option 3 ID : 4410092102978 Option 4 ID : 4410092102979 Status : Answered Chosen Option : B
IV
Calculate the multiplier (1тИТ100dтАЛ) for each discount. The shop with the smallest product of these multipliers offers the lowest selling price.
Marked price is constant for all shops. Shop I: 23% and 92% discounts. Shop II: 88% and 47% discounts. Shop III: 11% and 28% discounts. Shop IV: 63%, 76% and 86% discounts.
Selling┬аPrice=Marked┬аPrice├ЧтИПi=1nтАЛ(1тИТ100diтАЛтАЛ)
Calculate the multiplier (1тИТ100dтАЛ) for each discount. The shop with the smallest product of these multipliers offers the lowest selling price.
Many students mistake the largest sum of percentage discounts for the best deal; however, successive discounts are multiplicative, not additive.
Calculate Shop I multiplier
Successive discounts of 23% and 92% result in multipliers (1тИТ0.23)=0.77 and (1тИТ0.92)=0.08. The product is:
0.77├Ч0.08=0.0616
Calculate Shop II multiplier
Successive discounts of 88% and 47% result in multipliers (1тИТ0.88)=0.12 and (1тИТ0.47)=0.53. The product is:
0.12├Ч0.53=0.0636
Calculate Shop III multiplier
Successive discounts of 11% and 28% result in multipliers (1тИТ0.11)=0.89 and (1тИТ0.28)=0.72. The product is:
0.89├Ч0.72=0.6408
Calculate Shop IV multiplier
Successive discounts of 63%, 76% and 86% result in multipliers (1тИТ0.63)=0.37, (1тИТ0.76)=0.24, and (1тИТ0.86)=0.14. The product is:
0.37├Ч0.24├Ч0.14=0.012432
Compare results
Comparing the resulting values: 0.0616, 0.0636, 0.6408, and 0.012432. The smallest value is 0.012432, which corresponds to Shop IV.
0.012432<0.0616<0.0636<0.6408
B is correct because the product of the remaining price fractions for Shop IV is 0.012432, which is the lowest value among all shops.
This concept is identical to compound interest calculations where you multiply the growth factors (1+r/100). In discounts, we use decay factors (1тИТr/100).