1, the rule for finding defective products is that a defective product is mixed in, and the best method is grouping. The multiple of 3 is divided into three parts, and the difference cannot be divided equally by 1. When it is weighed on the balance, defective products appear immediately. Defective products refer to products that do not meet the quality standards.

2. Quality standards refer to the technical provisions on the structure, specifications, quality and inspection methods of products. Product quality standards are the technical basis for product production, inspection and quality evaluation. Product quality characteristics are generally expressed quantitatively.