Let the shopkeeper buy the article at ₹x
For him CP = ₹x and SP = ₹900 [0.5 Marks]
Net CGST paid to the government = ₹16.2, hence Net SGST paid to the government = ₹16.2 [0.5 Marks]
So, total GST paid = ₹16.2 + ₹16.2 = ₹32.4 [0.5 Marks]
GST on Output - GST on Input = ₹32.4 [0.5 Marks]
⇒18% of ₹900 - 18% of ₹x = ₹32.4 [0.5 Marks]
⇒ 18x100 = ₹ 162 - ₹32.4 = ₹129.6
⇒ x = ₹720
Hence, the amount paid by the shopkeeper is ₹720. [0.5 Marks]