Final answer:
The shopkeeper's loss per handkerchief sold is Rs. -453.
Step-by-step explanation:
To find the loss per handkerchief, we need to calculate the cost price per handkerchief and subtract the selling price per handkerchief from it. In this case, the shopkeeper buys 9 handkerchiefs for Rs. 540, so the cost price per handkerchief is Rs. 540 ÷ 9 = Rs. 60. She sells each handkerchief for Rs. 513. Therefore, her loss per handkerchief sold is Rs. 60 - Rs. 513 = Rs. -453.