It is given that the shopkeeper buys 80 articles for Rs 2,400.
Cost of one article = Rs 2400/80 = Rs 30
Profit percent = 16
Profit percent = Profit / C.P x 100
16 = Profit / Rs 30 x 100
Profit = Rs ( 16 x 30/100 ) = Rs 4.80
Selling price of one article = C.P. + Profit = Rs (30 + 4.80) = Rs 34.80