A shopkeeper claims to sell 450 kg rice at a cost price of Rs.40 per kg but uses a weight of 900 grams instead of a one kilogram weight. He makes a profit of Rs.2,520 by selling the remaining rice in the black market. The ratio of the black-market price to the original price per kg of rice is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 7 : 5.
Actual rice sold = 450 kg (claimed) × 0.9 = 405 kg
Profit from under-weighing = (450 − 405) × 40 = 1800
Black market profit = 2520 − 1800 = 720
Rice sold in black market = 45 kg
Let black market price be x, then:
45 × (x − 40) = 720
⇒ x − 40 = 16
⇒ x = 56
Required ratio = 56 : 40 = 7 : 5