A dealer in Bihar supplied goods to a dealer in Mumbai. The dealer in Mumbai buys :

(i) 40 articles for ₹ 800 each at 30% discount

(ii) 75 articles for ₹ 1,000 each at 20% discount.

If the rate of GST on the whole is 12%, find how much will the dealer at Mumbai pay to dealer in Bihar.

Selling price of 1 article = ₹ 800

Selling price of 40 articles = ₹ 800 x 40

= ₹ 3,200

Discount = 30% of ₹ 32,000

$\Rightarrow\dfrac{30}{100} \times ₹ 32,000\\[1em] \Rightarrow\dfrac{3}{10} \times ₹ 32,000\\[1em] \Rightarrow ₹ \dfrac{96,000}{10}\\[1em] \Rightarrow ₹ 9,600$

Taxable cost of articles = ₹ 32,000 - ₹ 9,600

= ₹ 22,400

GST = 12% of ₹ 22,400.

$\Rightarrow \dfrac{12}{100} \times ₹ 22,400\\[1em] \Rightarrow \dfrac{3}{25} \times ₹ 22,400\\[1em] \Rightarrow ₹ \dfrac{67,200}{25}\\[1em] \Rightarrow ₹ 2,688$

Amount of bill = ₹ 22,400 + ₹ 2,688

= ₹ 25,088

Selling price of 1 article = ₹ 1,000

Selling price of 75 articles = ₹ 1,000 x 75

= ₹ 75,000

Discount = 20% of ₹ 75,000

$\Rightarrow\dfrac{20}{100} \times ₹ 75,000\\[1em] \Rightarrow\dfrac{1}{5} \times ₹ 75,000\\[1em] \Rightarrow ₹ \dfrac{75,000}{5}\\[1em] \Rightarrow ₹ 15,000$

Taxable cost of article = ₹ 75,000 - ₹ 15,000

= ₹ 60,000

GST = 12% of ₹ 60,000.

$\Rightarrow \dfrac{12}{100} \times ₹ 60,000\\[1em] \Rightarrow \dfrac{3}{25} \times ₹ 60,000\\[1em] \Rightarrow ₹ \dfrac{1,80,000}{25}\\[1em] \Rightarrow ₹ 7,200$

Amount of bill = ₹ 60,000 + ₹ 7,200

= ₹ 67,200

Total amount the dealer at Mumbai will pay to dealer in Bihar = ₹ 25,088 + ₹ 67,200

= ₹ 92,288

Hence, amount of bill = ₹ 92,288.