A trader a weighing balance that shows 1300 g for a kg. He further marks up his cost price by 15%. The net profit percentage is :

49.5%

Let the cost price per g be Rs. 1

So, cost price of 1300 g = Rs. 1300

Marked price of 1300 g = 1300 × 115%

⇒ Rs. 1495

Now, the trader gives 1000 g instead of 1300 g

So, his profit = 1495 - 1000    [As cost price of 1000 g is Rs. 1000]

⇒ 495

Profit% = \(\frac{495}{1000}\) × 100

⇒ 49.5%