I am a re-seller and paid the GST while purchasing. Lets say, I have bought an item for Rs 1000 + GST10%.  So Total amount is Rs 1100.00 . Now I am selling the same item to the customer with some profit margin Rs 200. So My question here is, Do I need to charge the same tax(GST10%) from the customer? Which means (PurchaseAmount+ ProfitMargin)+ GST10%?  or how should I charge?