A dishonest dealer marks up the price of his goods by 20% and gives a discount of 10% to the customer. Besides, he also cheats both his supplier and his buyer by 100 grams while buying or selling 1 kilogram. Find the percentage profit earned by the shopkeeper?

Explanation:-

While buying,

He buys 1100 gram instead of 1000gram.
Suppose he bought 1100 grams for Rs. 1000.

While selling,

He sells only 900 grams when he takes the money for 1 kg.
Now, according to the problem,
he sells at a 8% profit (20% markup, 10% discount).
Hence, his selling price is Rs. 1080 for 900 grams.
Now,
1100grams for Rs. 1000
Hence, 1188 grams for Rs. 1080
Selling: 900 grams for Rs. 1080.
Hence, % profit = 288/900 = 32%.
(using goods left by goods sold formula).