A shopkeeper is ready to sell his goods at one of the following four…

The scheme beneficial for the customer depends on agg. discount

(a) 10% , 10%

MP  ×\(\frac{9}{10}\) × \(\frac{9}{10}\) = MP × \(\frac{81}{100}\) ⇒ Discount 19%

(b) 15%, 5%

MP × \(\frac{17}{20}\) × \(\frac{19}{20}\) = MP × \(\frac{323}{400}\)  ⇒ Discount 19.25%

(c)  12%, 8%

MP × \(\frac{22}{25}\) × \(\frac{23}{25}\) = MP × \(\frac{506}{625}\)  ⇒ Discount 19.04%

(d) 16%, 4%

MP × \(\frac{21}{25}\) × MP\(\frac{24}{25}\) = MP × \(\frac{504}{625}\)  ⇒ Discount 19.36%

∴ scheme (d) yields best discount

Ans. d) 16%, 4%

 

*Alternate way:

The maximum discount between two percentages is always beneficial for the customer. i.e. difference b/w 16 & 4 is 12 and that is maximum as compare to others. Hence, (d) is answer.