Question
After increase in the price of coffee by 25%, a person
is able to buy 4 kg less for Rs. 1,640. Find the original and increased price of the coffee per kg.  ÂSolution
Let the original price (O.P.) be Rs. x per kg. ∴ New price (N.P.) = 125% of x = Rs. 5x/4 per kg. Quantity of coffee the person could buy at original price = 1640/x kg. Quantity of coffee he can buy at new price = (1640 × 4)/5x = 1312/x kg Given that difference between the quantity at original price and at new price is 4 kg. ∴ 1640/x - 1312/x = 4 ⇒ 328/x = 4 ⇒  = 82 ∴ O.P. = Rs.82 and N.P. = Rs. 5x/4 = (5 × 82)/4 = Rs.102.5
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