Problema Solution
A shopkeeper buys an article at a rebate of 20% on its marked price and then spends Rs.300 on its transportation, etc. If he sells the article for Rs.4160 [including sales tax at the rate of 4% of the marked price], find the shopkeeper's profit percent.
Answer provided by our tutors
let 'x' be the marked price
the money the shopper spends on buying: x - 0.20x + 300 = 0.8x + 300
the money he earns from the sale: x + 0.04x = 4160 => x = $4000
the profit is: 4000 - (0.8x + 300) = 4000 - (0.8*4000 + 300) = $500
the profit percent: 500/(0.8*4000 + 300) = 0.143 or 14.3%