A shopkeeper marks his articles at 30% above the cost price and allows the purchaser a discount of 20% for cash buying. What profit per cent does he make?

4%

Let the cost price = 100

then the marked price = 130

Discount = 20%

Then the sellilng price = 80% of the marked price = 80% of 130 = 104

Profit = 104 - 100 = 4

Profit % = 4 × \(\frac{100}{100}\) = 4%