A shopkeeper bought 80 kg of rice at a discount of 10%. Besides 1 kg rice was offered free to him on the purchase of every 20 kg rice. If he sells the rice at the marked price, his profit percentage will be:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 
Let the price of 1kg of rice = Rs. 100
He bought 80kg of rice at Rs. 90 which costs = 90 × 80 = Rs. 7200
He has (80 + 4)kg of rice in which, he got 4kg free which he sold at Rs. 100
⇒ 84 × 100 = Rs. 8400
⇒Profit percentage = [(8400 - 7200) / 7200] × 100
⇒ [1 / 6] × 100 = 16.67% or 16 (2/3)%