Raman bought two items, A & B, from a shop. He paid Rs 1680 including GST of 12% for A and Rs 1265 including GST of 15% for B. The shopkeeper did not give him the receipt. Find the amount of GST not paid by the shopkeeper to the Government.

It is given, Raman bought A at a price inclusive of 12% GST = Rs 1680

Let us assume the selling price of A be P then $$P\left(1+\ \frac{GST\ \%}{100}\right)$$ = 1680

=> $$P\left(1+\ \frac{12\ }{100}\right)$$ = 1680

=> $$P\ =\ 1680\times\frac{100\ }{112}$$

Therefore, P = Rs. 1500 and GST on item A = Rs. 180

Similarly, for item B

Let us assume the selling price of B be Q, then $$Q\left(1+\ \frac{GST\ \%}{100}\right)$$ = 1265

=> $$Q\left(1+\ \frac{15\ }{100}\right)$$ = 1265

=> $$Q\ =\ 1265\times\frac{100\ }{115}$$

Therefore, Q = Rs. 1100 and GST on item B = Rs. 165

Hence, the amount of GST not paid by the shopkeeper to the Government = 180+165 = Rs.345

The answer is option C.