Buy 2 get 2 free 1, which is equivalent to a discount.

According to the query of Baidu Library, buying two for one is 6.7 fold, which is equivalent to buying two for three, and the discount is (2/3)* 100%=67%=6.7%.

Discount means that when buying and selling goods, it is priced at a certain proportion of the original price. If it is 90%, it is called 10% discount or 10% discount. Discount bills of exchange with bank funds. The calculation formula is: discount amount per unit commodity = original price (or including discount price) × discount rate. Seller's actual net income = original price per unit commodity-discount amount.