Step 1: Find profit (in ₹)
Given: C.P. of article = ₹ 350
Profit =20%
Now, Profit (in ₹) = C.P. ×Profit100
=350×20100
=35×2
=70
Step 2: Find the selling price
Selling price = C.P. + Profit (in ₹)
=350+70
= ₹ 420
Hence, the selling price of the article is ₹ 420.