67% discount.

calculation method of discount: discount amount per unit of goods = original price (or including discount price) × discount rate.

generally speaking, the discount rate is the discount rate, and the discount rate = discount amount per unit of goods ÷ original price (or including discount price).

11111÷（11111＋5111）≈1.667。

Extended data

Operation sequence of four operations:

1. If there is only addition and subtraction or only multiplication and division, it is calculated from left to right.

2. If the first-level operation and the second-level operation exist at the same time, calculate the second-level operation first

3. If the first-level, second-level and third-level operations (that is, power, root and logarithm operations) exist at the same time, calculate the third-level operation first and then calculate the other two levels.

4. If there are brackets, the number in the brackets should be counted first (no matter what level it is, it should be counted first).

5. In brackets, you should also calculate the third level first, and then go to the second and first levels.