A dishonest dealer marks up the price of his goods by 20% and gives a discount of 10% to the customer. He also uses a 900 gram weight instead of a 1 kilogram weight. Find his percentage profit due to these maneuvers?

Answer: Option A

Let CP = Rs. 1 per gram
Then SP of 1000gram is 1000 + 20% of 1000 = Rs. 1200
Now Dealer gives 10% discount = 1200 - 10% of 1200 = Rs. 1080

Then, Dealer is dishonest and sells 900 g is 1080
And, CP of 900 grams is 900
Profit = 1080 - 900 = 180
∴ % profit = $$\frac{180\times 100}{900}$$   = 20%