A shopkeeper buys an article whose printed is rs 4000 from a wholesaler at a discount of 20% . the rate of sales tax under vat on the article is 8%.

100% - 20% + 8% = 88% = 0.88.

Cost = 0.88 * 4000 = $3,520.

To find the price at which the shopkeeper bought the article, we need to calculate the discount amount. The discount is given as 20% of the printed price, which is Rs 4000.

Discount = 20% of Rs 4000 = 0.20 * Rs 4000 = Rs 800

After deducting the discount from the printed price, we get the amount at which the shopkeeper bought the article:

Price at which the shopkeeper bought the article = Printed price - Discount = Rs 4000 - Rs 800 = Rs 3200

Next, we need to calculate the sales tax on the article at a rate of 8% under VAT. To do this, we can multiply the price at which the shopkeeper bought the article by the sales tax rate:

Sales tax = 8% of Rs 3200 = 0.08 * Rs 3200 = Rs 256

Finally, we can calculate the total cost incurred by the shopkeeper, which is the price at which the shopkeeper bought the article plus the sales tax:

Total cost = Price at which the shopkeeper bought the article + Sales tax = Rs 3200 + Rs 256 = Rs 3456