Ten percent.

The difference between 30% off and 60% off is one discount, which is a difference of 10%.

Credit card installment repayment generally refers to a single purchase that meets a certain amount, swiping the card once, and then repaying it in parts such as 3, 6, 12, 24, etc. The more installments you get, the more you need to pay. The higher the handling fee, so 40% off the handling fee is a big discount.