1. Divide into 3 parts, each part is 5 pieces, and weigh two pieces at a time. If they are the same, divide the other part into 3 parts, namely 3 pieces \3 pieces \2 pieces, and weigh them once. If they are the same, the defective products are part of 2 pieces, divided into 2 parts, and each piece should be weighed once.

2. Divide into 3 parts, each part is 5 pieces, and weigh two pieces at a time. If it is not the same, there will be defective products in the heavy part. Five pieces will be divided into three pieces, that is, two pieces \ two pieces \ 1 piece, and two pieces will be weighed once. If it is the same, the rest is defective. If they are not the same, the heavy part will be divided into two parts, which will be 65430 pieces per minute.